Oxford Handbook of Geriatric Medicine (2 edn)
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The ageing brain and nervous system
As in other systems intrinsic ageing (occurs in all) is often hard to distinguish from extrinsic ageing mechanisms (caused by disease processes). See 
‘Cognitive ageing’, p.204 for discussion of cognitive ageing.
Histological changes in the brain include:
Each neuron has fewer connecting arms (dendrites)
Around 20% of brain volume and weight are lost by the age of 85
There is deposition of pigment (lipofuscin) in the cells and oxidative damage in mitochondria
The presence of senile plaques and neurofibrillary tangles increases with age but they are not diagnostic of dementia (Table 7.1)
| Age-related change | Consequence |
|---|---|
Loss of neurons (cannot be regenerated) Decrease in brain weight (by around 20% at age 85) | Cerebral atrophy common on brain scans (although this does not correlate well with cognitive function) |
Some neurons become demyelinated and have slowed nerve conduction speed and increased latency (time taken to recover before transmitting next impulse) | Reflexes which have long nerve tracts, eg ankle jerks, can be diminished or lost |
Minor sensory loss, eg fine touch/vibration sense, may be lost distally | |
Neurotransmitter systems alter, eg cholinergic receptors decrease | Increased susceptibility to some neuromodulating drugs |
Increasing frequency of periventricular white matter changes seen on cerebral imaging | Probably not a normal finding |
Significance unclear—assumed to be representative of small-vessel vascular disease but poor postmortem correlation |
| Age-related change | Consequence |
|---|---|
Loss of neurons (cannot be regenerated) Decrease in brain weight (by around 20% at age 85) | Cerebral atrophy common on brain scans (although this does not correlate well with cognitive function) |
Some neurons become demyelinated and have slowed nerve conduction speed and increased latency (time taken to recover before transmitting next impulse) | Reflexes which have long nerve tracts, eg ankle jerks, can be diminished or lost |
Minor sensory loss, eg fine touch/vibration sense, may be lost distally | |
Neurotransmitter systems alter, eg cholinergic receptors decrease | Increased susceptibility to some neuromodulating drugs |
Increasing frequency of periventricular white matter changes seen on cerebral imaging | Probably not a normal finding |
Significance unclear—assumed to be representative of small-vessel vascular disease but poor postmortem correlation |
Tremor
Tremor is more common with increasing age. It can be disabling and/or socially embarrassing. It is important to try to make a diagnosis as treatment is available in some cases.
Examine the patient first at rest and distracted (relaxed with arms supported on lap, count backwards from 10), then with outstretched hands and finally during movement (pointing or picking up a small object). Tremors fall roughly into three categories
Rest tremor—disappears on movement and is exaggerated by movement of the contralateral side of the body. Commonest cause—Parkinson's disease. It is usually associated with increased tone
Postural tremor—present in outstretched limbs, may continue during action but disappears at rest. Commonest cause—benign essential tremor
Action tremor—exaggerated with movement. When the tremor is maximal at extreme point of movement it is called an intention tremor. Commonest cause—cerebellar dysfunction
Benign essential tremor
The classic postural tremor of old age, worse on action (eg static at rest but spills tea from teacup) may have head nodding (titubation) or jaw/vocal tremor, legs rarely affected. May be asymmetrical
About half the cases have a family history (autosomal dominant)
Presents in middle age, occasionally earlier and worsens gradually
Often more socially embarrassing than physically impairing
Improved by alcohol, gabapentin, primidone and β-blockers but these often unacceptable treatments in the long term. Worth considering β-blockers as first choice in treatment with coexistent hypertension
Weighted wristbands can reduce tremor and improve function
Parkinson's disease
(see ‘Parkinson's disease: presentation’, p.158)
Cerebellar dysfunction
The typical intention tremor is associated with ataxia.
Acute onset is usually vascular in older patients
Subacute presentations occur with tumours (including paraneoplastic syndrome), abscesses, hydrocephalus, drugs (eg anticonvulsants), hypothyroidism or toxins
Chronic progressive course is seen with:
Alcoholism (due to thiamine deficiency—always give thiamine 100mg od orally or iv preparation if in doubt, it might be reversible)
Anticonvulsant (eg phenytoin—may be irreversible if severe, commoner with high plasma levels but can occur with long-term use at therapeutic levels)
Paraneoplastic syndromes (anti-cerebellar antibodies can be found, eg anti-Yo and anti-Hu found in cancer of ovary and bronchus)
Multiple sclerosis
Idiopathic cerebellar atrophy
Many cases defy specific diagnosis. Consider multisystem atrophy
Other causes of tremor
(Table 7.2)
| Diagnosis | Recognition and characteristics | Management |
|---|---|---|
Thyrotoxicosis | Fine resting tremor This is actually commoner in younger patients | see |
Rigors | Sudden onset coarse tremor with associated malaise and fever | Diagnose and treat underlying cause |
Asterixis (tremor and incoordination) with hepatic, renal or respiratory failure | Coarse postural tremor in a sick patient with physiological disturbance A less dramatic, often fine, tremor can occur with metabolic disturbance such as hypoglycaemia or hypocalcaemia | Diagnose and treat underlying condition |
Drug withdrawal, eg benzodiazepines, SSRIs, barbiturates | Always consider when patient develops tremor ± confusion soon after admission | For therapeutic drugs recommence and consider gradual controlled withdrawal at later date |
Alcohol withdrawal | Always take an alcohol history. Tremor ± confusion develops soon after admission | Consider treatment with, eg chlordiazepoxide and thiamine |
Drug side effects, eg lithium, anticonvulsants | Check serum levels are in therapeutic range. Consider a different agent | |
Anxiety/stress—increased sympathomimetic activity | Fine tremor | Rarely necessary to consider β-blockers |
Orthostatic tremor—rare, benign postural tremor of legs | Fine tremor of legs on standing diminished by walking/sitting. Can palpate muscle tremor in legs. Patient feels unsteady but rarely falls | Provide perching stools etc to avoid standing for long |
| Diagnosis | Recognition and characteristics | Management |
|---|---|---|
Thyrotoxicosis | Fine resting tremor This is actually commoner in younger patients | see |
Rigors | Sudden onset coarse tremor with associated malaise and fever | Diagnose and treat underlying cause |
Asterixis (tremor and incoordination) with hepatic, renal or respiratory failure | Coarse postural tremor in a sick patient with physiological disturbance A less dramatic, often fine, tremor can occur with metabolic disturbance such as hypoglycaemia or hypocalcaemia | Diagnose and treat underlying condition |
Drug withdrawal, eg benzodiazepines, SSRIs, barbiturates | Always consider when patient develops tremor ± confusion soon after admission | For therapeutic drugs recommence and consider gradual controlled withdrawal at later date |
Alcohol withdrawal | Always take an alcohol history. Tremor ± confusion develops soon after admission | Consider treatment with, eg chlordiazepoxide and thiamine |
Drug side effects, eg lithium, anticonvulsants | Check serum levels are in therapeutic range. Consider a different agent | |
Anxiety/stress—increased sympathomimetic activity | Fine tremor | Rarely necessary to consider β-blockers |
Orthostatic tremor—rare, benign postural tremor of legs | Fine tremor of legs on standing diminished by walking/sitting. Can palpate muscle tremor in legs. Patient feels unsteady but rarely falls | Provide perching stools etc to avoid standing for long |
Neuropathic pain/neuralgia
This describes pain originating from nerve damage/inflammation. It is often very severe and debilitating and seems to be more common in older people. The pain is usually sharp/stabbing and is often intermittent being precipitated by things like movement and cold.
Post-herpetic neuralgia
Severe burning and stabbing pain in a division of nerve previously affected by shingles
Shingles and subsequent persisting neuralgia is much more common in older patients
Pain may be triggered by touch or temperature change
May go on for years, be difficult to treat and have major impact on quality of life
Prevent by starting antivirals within 72hr of rash (eg famciclovir)
See ‘HOW TO . . . Treat neuralgia’, p.157 for treatment
Trigeminal neuralgia
Severe unilateral stabbing facial pain, usually V2, V3 rather than V1
Triggers include movement, temperature change, etc.
Time course—years with relapse/remission
Depression and weight loss can result
Differential diagnoses include temporal arteritis, toothache, parotitis and temporomandibular joint arthritis
Consider neuroimaging especially if there are physical signs, ie sensory loss or other cranial nerve abnormality suggestive of secondary trigeminal neuralgia
Bilateral trigeminal neuralgia suggests multiple sclerosis
See ‘HOW TO . . . Treat neuralgia’, p.157 for treatment
Neuralgia can also occur with
Malignancy
Cord compression
Neuropathy
This can be very debilitating and treatment is difficult. There is often coexistent depression, so always think of this and treat appropriately.
Simple measures include
Distraction
Relaxation techniques
Allaying fears (usually about serious underlying pathology)
Acupuncture
Heat/cold treatment
Osteopathy/massage (to reduce associated muscle spasm)
Use of TENS machines (transcutaneous nerve stimulation)
Support groups, eg 
www.tna.org.uk
Medications
Topical treatments, eg lidocaine, capsaicin
Traditional analgesics (paracetamol, NSAIDs, opiates) although these are usually not very effective
Anti-spasticity drugs, eg baclofen. Used especially in trigeminal neuralgia, they treat any muscle spasm that exacerbates the pain
Mainstay of treatment is the neuromodulating drugs which may give superior pain control but often have important side effects.
Examples include:
Antidepressants with neuroadrenergic modulating abilities, eg amitriptyline, duloxetine. Start with a low dose and titrate up slowly. Eventual doses may be similar to those used in younger patients
Anticonvulsants, eg gabapentin, pregabalin (postherpetic neuralgia) or carbamazepine, oxcarbazepine, valproate (trigeminal neuralgia). Start with a low dose and titrate up slowly
The main side effects from these drugs are sedation and confusion, and reaching a therapeutic dose may be limited by this problem.
Other options
Nerve blocks or spinal stimulation, which can usually be accessed via a specialist pain clinic
Surgery, eg nerve decompression, or treatment with heat or lasers. May provide relief but can result in scarring and numbness
Parkinson's disease: presentation
A common, idiopathic disease (prevalence 150/100 000) associated with inadequate dopamine neurotransmitter in brainstem. There is loss of neurons and Lewy body formation in the substantia nigra. The clinical syndrome is distinct from Lewy Body dementia (See ‘Dementia and parkinsonism’, p.214 for treatment) but there is overlap in some pathological and clinical findings leading to suggestions they might be related conditions.
Presentation
The clinical diagnosis of Parkinson's disease is based on the UK Parkinson's disease brain bank criteria and should include:
Bradykinesia (slow to initiate and carry out movements, expressionless face, fatigability of repetitive movement)
Plus at least one of the following:
Rigidity (cogwheeling = tremor superimposed on rigidity)
Tremor (‘pin-rolling’ of hands—worse at rest)
Postural instability
Other clinical features:
Gait disorder (small steps)
Usually an asymmetrical disease
No pyramidal or cerebellar signs but reflexes are sometimes brisk
Non motor symptoms are common and should be asked about (see ‘Non-motor symptoms of Parkinson's disease’, p.158)
Depression (treat appropriately)
Psychosis (may relate to medications; avoid typical antipsychotics as they may worsen the motor features; atypicals such as quetiapine or olanzapine can be tried)
Dementia and hallucinations can occur in late stages but drug side effects can cause similar problems. If features suggest Lewy body dementia a trial of anticholinesterases may be warranted
Sleep disturbance (treat restless legs, review medications, advise about driving if sudden onset sleep, daytime hypersomnolence may be treated with modafinil)
Falls (usually multifactorial, see ‘Assessment following a fall’, p.104)
Autonomic features are generally late features, but common in older patients. They should be sought and actively managed:
Weight loss
Dysphagia
Constipation
Erectile dysfunction
Orthostatic hypotension
Excessive sweating
Drooling
Investigations
Diagnosis is clinical, and once suspected should be reviewed by a Parkinson's disease specialist
Trials of treatment may be done, with review of the diagnosis if there is no improvement, but single dose levodopa ‘challenge’ tests are no longer performed
Brain imaging (eg CT) can be used to illustrate other conditions that may mimic Parkinson's disease (eg vascular disease)
Specialist scans are becoming more widely used to assist diagnosis (eg consider 123I-FP-CIT single photon emission computed tomography (SPECT), commonly known as DatSCAN™ after the radiolabelled solution used)
Parkinson's disease: management
Should be overseen by a Parkinson's disease specialist clinic.
Drugs
It is not possible to identify a universal first-choice drug therapy for either early Parkinson's disease or for adjuvant drug therapy for later stages.
Consider the short- and long-term benefits and risks of each treatment, along with lifestyle and clinical factors. Discussion with the patient is key.
Initiation treatment is started with one of the following:
Levodopa plus decarboxylase inhibitor (prevents peripheral breakdown of drug) (co-beneldopa/co-careldopa). Start low and titrate to symptoms
Dopamine agonists (ropinirole, pergolide, cabergoline). Psychiatric side effects, postural hypotension and nausea often limit therapy
MAOI (selegiline). The newer buccally absorbed preparation is better tolerated and useful in swallowing difficulties. These drugs have many interactions with antidepressants and should be used with care by a specialist
Adjuvant treatment may be needed as the disease progresses. Firstly increase doses or add a second agent from the list already given then consider:
COMT inhibitor (entacapone). Will smooth fluctuations in plasma levodopa concentrations. Give with each levodopa dose—sometimes will need levodopa dose decrease. Stains urine orange
Amantadine—weak dopamine agonist which can reduce dyskinetic problems
Apomorphine—subcutaneous (s/c) injections. Specialist treatment- rarely useful in older patients except to cover periods of nil by mouth
Anticholinergics (benzhexol, orphenadrine) are mild anti-parkinsonian drugs rarely useful in elderly patients due to severe psychiatric side effects. They do have a beneficial effect on tremor and are possibly the drug of choice where tremor is more of a problem than bradykinesia.
Surgery
Ablation (eg pallidotomy) and stimulation (electrode implants) used in highly selected populations. Older patients often excluded due to high operative risk.
Other therapeutic options
Patients and carers benefit from regular review by a specialist doctor or nurse. Many services now have specialist Parkinson's disease nurses
A course of physiotherapy can be helpful to boost mobility
Occupational therapy plays a vital role in aids and adaptations for disability
Speech and language therapists, along with dieticians can help when swallowing becomes a problem
Occasionally inpatient assessment is helpful but be aware that hospital routines can rarely match home treatment and some patients deteriorate in hospital
Parkinson's UK ( www.parkinsons.org.uk) has plenty of information and advice for patients and carers
This situation arises quite commonly in advanced disease during a hospital admission.
A patient with advanced disease, admitted for another reason (eg sepsis) may miss an oral dose of medication (eg because they are unwell, or because the drug is not immediately available). In some this will be well tolerated; in others there will be a rapid decline in function and loss of swallow, with a downward spiral unless promptly managed.
Other situations in which oral medication may not be possible:
Perioperatively when patient is nil by mouth
When an ileus or other cause makes poor drug absorption likely
After a stroke
▶Omission of medication will (for most patients with Parkinson's disease) lead to a decline in function, so continuation of treatment is key.
Reducing the risk
Plan ahead—patients should be educated about the importance of taking medication on time, and always bring their own medication with them if they come into hospital and be encouraged to self medicate where possible
If surgery is elective, then get specialist advice about medication as part of the preoperative assessment. Aim for local or regional anaesthesia if possible
Have protocols in place for the urgent care of Parkinson's disease patients
Ensure that wards have Parkinson's disease drugs readily available
Early action
Use nasogastric (NG) tubes early if swallow is impaired
Relax nil by mouth rules preoperatively for Parkinson's disease drugs
Use antiemetics when vomiting
Medication
Use a different preparation eg levodopa dispersible down an NG tube, buccal selegiline
Use an enteral preparation eg apomorphine (subcutaneous delivery) or rotigotine (patch delivery). Advice will be needed from a specialist about doses that are equivalent to their usual medication
Further reading
(Table 7.3)
Wearing off—progression of disease—patients require higher doses or more frequent dosing to produce same effect | Possible that levodopa itself is toxic to neurons and enhances progression. In younger patients/milder disease start with selegiline or dopamine agonists |
Dyskinesias | Reduce levodopa dose if possible (either alone or with addition of an agonist). Add amantadine |
Motor fluctuations with choreodystonic ‘on’ phases and freezing ‘off ’ phases. These worsen with duration of treatment | Reduced levodopa dose more frequently (dose fractionation) or controlled release preparations or add entacapone or add dopamine agonist |
Other drug side effects (confusion and hallucinations, constipation, urinary retention, nausea and vomiting) are a particular problem in elderly and often limit treatment to sub-ideal levels | Domperidone (30mg tds orally) is the best antiemetic |
In general patients prefer dyskinetic side effects than ‘off spells’—relatives/carers may find the opposite easier to cope with especially if patient confused or falling when ‘on’ | Ensure you talk to the patient as well even if it is easier to talk to the carer. Compromise may be necessary |
Quantifying response to treatment is very difficult | Get patients/carers to fill in a 24hr chart. A formal quantified drug trial by therapists can be very helpful |
Morning stiffness | Use a rapid-acting drug (eg Madopar® dispersible) in bed on waking or try a long-acting drug last thing at night |
End-stage disease | Ultimately drug responsiveness so poor and side effects so marked that decreasing and withdrawing therapy may be appropriate. Palliative treatment and social support important |
Wearing off—progression of disease—patients require higher doses or more frequent dosing to produce same effect | Possible that levodopa itself is toxic to neurons and enhances progression. In younger patients/milder disease start with selegiline or dopamine agonists |
Dyskinesias | Reduce levodopa dose if possible (either alone or with addition of an agonist). Add amantadine |
Motor fluctuations with choreodystonic ‘on’ phases and freezing ‘off ’ phases. These worsen with duration of treatment | Reduced levodopa dose more frequently (dose fractionation) or controlled release preparations or add entacapone or add dopamine agonist |
Other drug side effects (confusion and hallucinations, constipation, urinary retention, nausea and vomiting) are a particular problem in elderly and often limit treatment to sub-ideal levels | Domperidone (30mg tds orally) is the best antiemetic |
In general patients prefer dyskinetic side effects than ‘off spells’—relatives/carers may find the opposite easier to cope with especially if patient confused or falling when ‘on’ | Ensure you talk to the patient as well even if it is easier to talk to the carer. Compromise may be necessary |
Quantifying response to treatment is very difficult | Get patients/carers to fill in a 24hr chart. A formal quantified drug trial by therapists can be very helpful |
Morning stiffness | Use a rapid-acting drug (eg Madopar® dispersible) in bed on waking or try a long-acting drug last thing at night |
End-stage disease | Ultimately drug responsiveness so poor and side effects so marked that decreasing and withdrawing therapy may be appropriate. Palliative treatment and social support important |
Further reading
Defined as the failure to resist an impulse, drive or temptation to perform an act that is harmful to the person or others
Tend to occur after the initiation of dopaminergic therapy in those who are susceptible, and abate with dose reduction
Examples include:
Hypersexuality (see ‘Sexual function’, p.528)
Pathological gambling
Compulsive buying
Aimless wandering
Repetitive activities (eg arranging objects)
Dopamine dysregulation syndrome (addictive use of dopaminergic drugs in a Parkinson's disease patient with other impulse control behaviours)
Diseases masquerading as Parkinson's disease
The majority of slow, stiff or shaky older patients on geriatric wards do not have true Parkinson's disease (Table 7.4). As many as 1 in 4 diagnoses of Parkinson's disease made by non-specialists are incorrect. It is important to get the diagnosis right or you will subject patients needlessly to the harmful side effects of medications. Coexistence of more than one syndrome can further complicate diagnosis.
Atherosclerotic pseudo-parkinsonism/multi-infarct dementia: Due to neurovascular damage—consider in those with stroke/TIA or with atherosclerotic risk factors, eg hypertension. Short-stepping, wide-based unstable gait with relative preservation of arm and facial movements (lower body parkinsonism). Head scan may show lacunae or white matter change
Benign essential tremor: Often inherited (autosomal dominant), worse on action (spills tea from teacup), improved by alcohol and β-blockers, may have head nodding or vocal tremor
Lewy body dementia: Lewy bodies are widely present throughout cortex not predominantly in substantia nigra as with true Parkinson's disease. Psychiatric symptoms, eg visual hallucinations tend to precede physical ones
Drug-induced parkinsonism: Neuroleptics are the commonest cause but remember that prochlorperazine for dizziness and metoclopramide for nausea are also causes. Some irritable bowel treatments contain neuroleptics
Other causes: Alzheimer's disease, hydrocephalus, and even severe polyarthritis can sometimes cause diagnostic confusion. Rare differential diagnoses include Wilson's disease, Pick's disease, carbon monoxide poisoning, multiple head injuries (ex-boxers) and postencephalitis or anoxic brain injury
| True Parkinson's disease | Pseudo-parkinsonism (especially atherosclerotic) | |
|---|---|---|
Response to L-dopa | Good Develop dopa dyskinesias | Poor or transient Dopa dyskinesias unusual |
Age of onset | 40–70 | 70+ |
Tremor | Unilateral or asymmetrical Resting tremor prominent | Absent or mild |
Progression | Slow progression/long history | Rapid progression |
Dementia | Only at late stage | Prominent or early |
Instability/falls | Late | Early and prominent |
Dysphonia, dysarthria or dysphagia | Late | Early and prominent |
Other neurology (pyramidal signs, downgaze palsy, cerebellar signs) | Rare | Common |
| True Parkinson's disease | Pseudo-parkinsonism (especially atherosclerotic) | |
|---|---|---|
Response to L-dopa | Good Develop dopa dyskinesias | Poor or transient Dopa dyskinesias unusual |
Age of onset | 40–70 | 70+ |
Tremor | Unilateral or asymmetrical Resting tremor prominent | Absent or mild |
Progression | Slow progression/long history | Rapid progression |
Dementia | Only at late stage | Prominent or early |
Instability/falls | Late | Early and prominent |
Dysphonia, dysarthria or dysphagia | Late | Early and prominent |
Other neurology (pyramidal signs, downgaze palsy, cerebellar signs) | Rare | Common |
Parkinson's-plus syndromes
This is a confusing array of rare disorders including:
Multi-system atrophy (aka Shy–Drager syndrome, olivopontocerebellar atrophy) with early autonomic failure (incontinence and postural instability), ataxia, parkinsonism, and pyramidal signs. Cognition intact
Progressive supranuclear palsy (aka Steele–Richardson–Olszewski disease) with up- and down-gaze palsy, axial rigidity and falls, dysarthria and dysphagia, and frontal lobe dementia
Further reading
Epilepsy
Primary epilepsy most commonly presents around the time of puberty but the incidence of new fits is actually higher in the over 70s (>100 per 100 000) because of the increasing amount of secondary epilepsy (caused by, eg brain ischaemia, subdural haematomas, brain tumours).
In addition fits can be precipitated by:
Metabolic disturbance (eg hyponatraemia)
Drugs (eg ciprofloxacin)
Infection (at any site but particularly meningitis/encephalitis)
Withdrawal from alcohol or drugs such as benzodiazepines
Wernicke's encephalopathy (due to thiamine deficiency in malnourished, eg alcoholics)
Many of these conditions are more common in older patients who also have a lower fit threshold for any given level of stimulus.
Diagnosis
See also ‘Syncope and presyncope’, p.108
An eye witness account is the most useful diagnostic tool
Look particularly for post-event confusion/drowsiness which is rare in cardiac syncope
The classic features of prodrome, tongue-biting and incontinence are not so useful in distinguishing cardiac from neurological syncope in older patients
Remember that cerebral hypoperfusion from any cause (eg bradycardia) can cause fits so epilepsy can coexist with other causes of syncope. In these cases treatment of the primary syncope/hypoperfusion is more effective than anti-epileptics. see ‘HOW TO . . . Distinguish syncope and seizures’, p.110
Investigations
Routine blood screening, CXR, and ECG to look for precipitants and differential diagnoses
CT scan is vital to exclude a structural lesion
EEGs can be helpful when positive but very commonly have non-specific changes and low sensitivity, ie normal EEG does not rule out epilepsy
General management
Ensure the patient is not taking medication that lowers the fit threshold (check the BNF—common examples include tricyclics, ciprofloxacin and phenothiazines. Think about over-the-counter drugs, eg Ginkgo biloba and stimulants such as cocaine)
Correct any metabolic derangement (eg glucose, sodium, sepsis)
Advise about driving restrictions—don't assume they don't drive
Detect and treat complications, eg aspiration, trauma, pressure injuries
Driving regulations and epilepsy
You have a duty to ensure that the patient informs DVLA. Patients have at least 1-year ban on driving for a first fit (unless a ‘provoked fit’, eg following brain surgery or stroke, when may be shorter period—individual decision). They can then reapply for licence as long as they remain fit-free. Patients must also refrain from driving for 6 months after withdrawing epilepsy medication.
Further information available at: www.dvla.gov.uk
Onset seizures (within a week, most commonly within 24hr) occur in 2–5% of strokes. Commoner with haemorrhages, large cortical strokes and venous infarction. Consider also alcohol/drug (especially benzodiazepine) withdrawal for early fits. Long-term anticonvulsants not usually prescribed unless fits recur.
After the first week stroke remains a risk factor for new epilepsy—first year 5% fit, subsequently 1.5% annual incidence. Many such patients develop transient neurological worsening (Todd's paresis) or permanent worsening without CT evidence of new stroke—in these patients it is usually worth considering long-term anticonvulsants.
Epilepsy may occur secondary to clinically ‘silent’ cerebral ischaemia and 3% of patients with stroke have a past history of fits, most occurring in the preceding year. Some epilepsy experts suggest that aspirin is prescribed for new-onset seizures in an elderly patient once structural lesions have been excluded.
Epilepsy: drug treatment
Acute treatment
Start with benzodiazepines (5–10mg rectal diazepam or 2–10mg iv Diazemuls® or 0.5–2mg lorazepam iv or intramuscularly (im))
If fits continue consider setting up loading dose infusion of phenytoin (use a cardiac monitor) until oral medication can be taken
Rarely the patient may need intubating and paralysing to stabilize them or to allow an urgent CT scan
Chronic treatment
Because of side effects and long duration of treatment most doctors will resist starting anticonvulsants until after a second fit, especially if the diagnosis is unclear or if there is a reversible precipitant. Presence of underlying structural abnormality or wishing to return to driving may tip the balance in favour of treatment
The choice of agent shows regional and personal variation
Most commonly used agents are similarly effective
Older agents include phenytoin, carbamazepine (both effective but may be sedative) and valproate (better tolerated but plasma levels are unhelpful in monitoring compliance or side effects)
Newer agents such as lamotrigine and levetiracetam are ‘cleaner’ and increasingly used as first line
All anticonvulsants have significant side effects, eg sedation, confusion, rash, tremor, and ataxia. Serious liver, blood and pulmonary side effects can also occur—ongoing monitoring to optimize dose and minimize side effects is necessary
Many anticonvulsants interact with each other as well as other drugs and can increase toxicity or reduce effectiveness—if in doubt consult a pharmacist. Gabapentin and pregabalin are less likely to interact with other medications and can be useful alternatives
Avoid abrupt withdrawal of antiepileptics—fits may be provoked
Partial seizures (eg face/arm twitching) are rarely dangerous and often distress bystanders more than the patient, but they can progress to secondary generalized seizures. The same drugs can be employed. Partial seizures often indicate structural lesions and an early CT scan is advisable
Sometimes a trial of anticonvulsants in patients with recurrent unexplained collapse can be revealing
Refer to an epilepsy specialist if control is proving difficult and multiple drugs are required
Neuroleptic malignant syndrome
Rare but important syndrome in patients taking neuroleptics (eg haloperidol, chlorpromazine, risperidone) with triad of:
Fever
Rigidity and tremor
Rhabdomyolysis with secondary renal failure (see ‘Rhabdomyolysis’, p.505)
▶Can be fatal (up to 30%) so early recognition is important.
Diagnosis
May arise at any time during treatment, ie patient may have recently:
Started (most common) or stopped neuroleptics
Increased the dose or been stable on them for a long time
Added a second drug, eg tricyclic antidepressant, lithium
Reintroduction of the offending drug at a later date may not reproduce symptoms. Contributing factors such as intercurrent illness, metabolic derangement may be important in the aetiology.
Clinical features
The patient looks unwell with fever, severe lead-pipe rigidity, bradykinesia, occasionally tremor and decreased conscious level
Time course: onset usually over 1–3 days, starts with rigidity/altered mental state
Seizures and abnormal neurological signs can occur
Autonomic dysfunction causes sweating, tachycardia, and hypertension
Multiorgan failure can occur, there is a leucocytosis, and creatinine kinase levels may be over 1000IU/L
Lumbar puncture, CT scan, and EEG are often required to exclude other diagnoses such as CNS infection
▶The most common cause of a similar presentation is sepsis in a patient with pre-existing cerebrovascular disease.
Management
Stop all neuroleptics. Cooling using paracetamol, fans and damp sponging. Intravenous fluids with careful monitoring of electrolytes and renal function. Dantrolene (direct muscle relaxant) can speed recovery. Short-term dialysis is sometimes required. Bromocriptine is used in some cases although there is limited evidence for efficacy.
Early transfer to intensive care unit may be wise—death most commonly occurs by hypoventilation/pneumonia or renal failure. There are sometimes persisting neurological sequelae.
Serotonin syndrome
A similar syndrome to neuroleptic malignant syndrome in patients taking serotonin reuptake inhibitors especially if combined with tramadol, tricyclic, or MAOI. Patients tend to be agitated and delirious rather than unconscious. Gastrointestinal symptoms (diarrhoea/vomiting) occur. Onset may be within 2hr, resolution usually quicker than NMS.
Motor neuron disease
A progressive idiopathic disease with selective degeneration of motor neurons causing weakness and wasting. There is a variety of manifestations depending on the site of damage; the commonest site for lesions is in the anterior horn cells of spinal cord (LMN), but descending motor pathway (UMN) may be affected in the corticospinal tracts, brainstem and motor cranial nuclei.
▶The combination of weakness and fasciculations should always prompt consideration of motor neuron disease.
Onset rises steeply with age with peak incidence late 50s/early 60s. Very rare before age 40. Overall prevalence 7 per 100 000 but incidence 1 per 10 000 age 65–85
Underdiagnosed in older patients (confused with cerebrovascular disease, myasthenia, especially bulbar onset forms, cervical myelopathy, motor neuropathy, syringomyelia, and paraneoplastic syndromes)
Slightly commoner in males
5% will have a family history (autosomal dominant is most common but can be recessive or X-linked)
History
Weakness, cramps and fatigue in limbs. Weakness usually begins in a focal area and spreads to contiguous muscles, onset in upper limbs is most common
Palatal and vocal cord paralysis can cause stridor, dysarthria, dysphagia, and aspiration pneumonia
Paresis of respiratory muscles can cause respiratory failure (may present to chest physicians/ITU)
Intellect, sensation, and continence are usually retained. Some forms associated with frontotemporal dementia (<5%), depression common
Examination
Look for wasting with fasciculation (LMN) especially in tongue, shoulders and legs. ▶Fasciculations may be a normal finding in hands and calves of older people
Head drop/droop can occur
Brisk reflexes, clonus and upgoing plantars (UMN). This is one condition that can cause absent ankle jerks and upgoing plantars
Atrophy and weakness are less specific signs
‘Donald Duck’ speech
Sensory changes should make you question the diagnosis
Investigations
Creatine kinase (CK) may be elevated
CT, MRI, and muscle biopsy are usually normal
Electromyography (EMG) shows denervation of muscles caused by anterior horn cell degeneration and is diagnostic
Clinical pictures
Diverse presentations and rate of progression including;
Amyotrophic lateral sclerosis (ALS) is the commonest form—classical picture of mixed UMN and LMN. Term used commonly in USA
Progressive pseudobulbar or bulbar palsy—speech and swallow predominantly affected
Primary lateral sclerosis—UMNs predominantly affected
Progressive muscular atrophy—LMNs predominantly affected
Treatment
Riluzole (sodium channel blocker) 50mg bd. Prolongs survival by a few months but not function. Licensed and endorsed by NICE for amyotrophic lateral sclerosis only. Expensive and should be supervised by specialist. Monitor liver function and check for neutropenia if febrile illness.
Supportive
Chest—antibiotics and physiotherapy, tracheostomy, non-invasive nocturnal ventilation (for diaphragmatic palsy, sleep apnoea)
Speech—early referral to speech therapy for communication aids
Nutrition—initially pureed food and thickened fluids. Malnutrition and aspiration are indications to consider artificial feeding (see ‘Nutrition’, p.356)
Muscle spasm—baclofen, physiotherapy
Mobility/independence—OT for wheelchairs and adaptations
Pain/distress—opiates or benzodiazepines (but beware respiratory suppression)
Other
This is devastating diagnosis to give to a patient—mean life expectancy is 2–5 years. Matters are often worse because there is often a considerable delay between symptoms and a concrete diagnosis being made (sometimes initial diagnosis may have been incorrect). Emphasize the retention of cognition and aspects of supportive care available. Offer regular follow up appointments
Specialist neurology/motor neuron disease nurses are available in some areas
Refer to Motor Neurone Disease Association for support
Consider enduring power of attorney and advance directives
Further reading
Peripheral neuropathies
Some minor degree of sensory loss in the feet and reduced or absent ankle jerks is so common in older patients (up to 50% of over 85 year olds) that some class this as a normal ageing change, but remember:
Even mild, asymptomatic neuropathies can contribute to postural instability and falls
The diagnosis is often missed because of non-specific symptoms and insidious onset with slow progression
Clinical features
There are signs of lower motor neuron weakness with wasting and loss of reflexes
Sensory loss often with joint position and vibration loss before touch and pain. This is classically in a ‘glove and stocking’ distribution, rather than dermatomal (see Appendix)
Neuralgia-type pain may be present (especially diabetes and alcohol). see ‘HOW TO . . . Treat neuralgia’, p.157
Autonomic failure and cranial nerve involvement can also occur
Severe cases may affect respiration
Classification
Try to determine if the signs are focal or generalized and whether they are predominantly sensory or motor because this can help identify the likely underlying pathology. Further classification by pathology (axonal or demyelinating) requires nerve conduction studies or biopsy.
The commonest pattern produces widespread symmetrical sensory loss (typically glove and stocking). This may be combined with distal muscle weakness (mixed motor and sensory neuropathy) or sometimes there is a pure motor neuropathy. Where signs are focal consider mononeuritis multiplex.
Causes
The causes are legion and often multiple in older patients. Idiopathic neuropathies are very common (25% defy diagnosis in most studies). The following list is not exhaustive:
Idiopathic
Diabetes
Carpel tunnel syndrome
Paraneoplastic syndromes (eg small cell lung cancer)
Alcoholism (often combined with vitamin deficiency)
Renal failure
B12 or folate deficiency
Guillain–Barré syndrome (commonest acute onset)
Hypothyroidism
Vasculitides (eg Wegner's granulomatosis)—actually multiple mononeuropathy
Drugs (eg isoniazid, nitrofurantoin, vincristine, amiodarone)
Paraproteinaemias and amyloid
Chronic inflammatory demyelinating polyradiculoneuropathy (rare autoimmune motor neuropathy)
Investigations
Always check B12, glucose, TFTs, serum and urine immunoglobulins, ESR and C-reactive protein (CRP) before labelling a neuropathy idiopathic
Look carefully for an occult tumour (eg breast examination and CXR)
Family history
Nerve conduction studies will confirm nerve damage and distinguish demyelination from axonal damage (which sometimes helps with differential diagnosis) but they are not always required in straightforward cases
Further specialist tests include immunology, tumour markers, lumbar puncture, molecular genetics tests, and nerve biopsy
Treatment
The important thing is to identify reversible causes quickly but even treatable causes rarely respond dramatically—the aim is usually prevention of further deterioration. Chronic inflammatory polyradiculoneuropathy is treated by steroids, plasma exchange and intravenous immunoglobulin but most other chronic neuropathies have no specific treatment. Supportive and symptomatic treatment (eg appropriate footwear, analgesia, environmental adaptation) is important.
This is an acute inflammatory demyelinating polyneuropathy.
Causes ascending paralysis, weakness beginning in the feet and hands and migrating towards the trunk
It can cause life-threatening complications, particularly if the respiratory muscles are affected or if there is dysfunction of the autonomic nervous system
The disease is usually triggered by an acute infection
This is a medical emergency which responds to iv immunoglobulins or plasmapheresis. These patients can deteriorate rapidly and should be managed in conjunction with specialist neurology units. Even patients who look well should have their vital capacity measured daily to warn of impending respiratory failure.
▶The main hurdle is recognizing the diagnosis.
Subdural haematoma
A condition which is much more common in old age because as the brain shrinks the veins which lie between it and the skull are much more likely to get torn following trauma (even minor injury). Older people are also more likely to have falls/head injuries and are more commonly on predisposing drugs (eg aspirin, warfarin). Other risk factors include alcoholism, epilepsy, and haemodialysis.
Features
▶Subdurals frequently present with very non-specific symptoms in a frail confused patients. A high index of suspicion is required.
Subdurals can occur acutely (and present within hours of an accident) or more slowly as the classical ‘chronic subdural haematoma’ although this distinction doesn't help guide management
A history of head injury occurs in only about half
Common features include drowsiness and confusion (rarely fluctuant), postural instability, progressive focal neurology (eg hemiparesis, unequal pupils), headache, blurred vision
Rarely transient neurology (mimicking TIA) or parkinsonism can occur
Some patients are asymptomatic and large collections can be incidental findings
Examine for papilloedema, focal neurology, and long tract signs
Diagnosis
CT head scan—look for crescent-shaped haematoma compressing sulci (hypodense/black is old blood, hyperdense/white indicates recent bleeding) and midline shift
All patients who have new UMN signs with confusion and or drowsiness should be scanned
It is harder to decide when to scan a confused patient without such signs—most agree it is reasonable to look for other causes of acute confusion before asking for a head scan as long as the patient is being observed for any change in neurological signs or conscious level
Have a lower threshold for scanning patients on aspirin or warfarin and for those who have evidence of falls, particularly facial bruising. MRI is slightly superior and useful when CT changes are subtle (an isodense phase occurs on CT in transition between hyperdense and hypodense changes) or very small haematomas are suspected
Management
Decisions are usually made in conjunction with the local neurosurgical team (although in practice only about 1/3 of patients will end up having surgery).
Stop aspirin and reverse warfarin therapy if possible.
Observation (with or without dexamethasone to reduce intracerebral pressure) is frequently used in:
Asymptomatic patients
Those with small bleeds who are stable/improving
Those not fit for transfer/surgery
When conservative management is adopted, record conscious level (GCS— see Appendix, ‘Glasgow Coma Scale’, p.696) and any focal neurology at least daily or if there is any change. Any deterioration should prompt repeat CT scan and reconsideration of surgery.
Burrhole surgery is not complex and is done under local anaesthetic. Recovery after surgery can be dramatic. Complications include re-bleeding and seizures. Use symptoms (especially conscious level) not CT appearance to decide on surgery. Mortality is around 10%—highest with depressed conscious level and bilateral haematoma. Those left with residual neurology should receive rehabilitation as in stroke.
Sleep and insomnia
With increasing age less sleep is needed (approximately 1hr less than young adults), circadian rhythm is less marked and sleep becomes more fragmented with greater difficulty getting to sleep. Deep (stage 3 and 4) sleep is reduced but dreaming sleep/REM (rapid eye movement) is preserved.
Insomnia is a symptom which correlates poorly with observed actual sleep time (ie patients who complain of poor sleep may be observed by nurses/family to sleep well while those who sleep very little do not necessarily complain). It can be very distressing and is associated with increased morbidity and mortality. Around 25% of elderly people have chronic insomnia—even higher rates with psychiatric and medical conditions. Insomnia is a particular problem in an unfamiliar noisy ward environment and doctors are often under considerable pressure to prescribe sedatives.
Treatment of insomnia
First ensure that underlying causes are looked for and treated:
Pain at night—consider using analgesics with sedative side effects eg opiates
Nocturnal urinary frequency, eg due to polyuria, peripheral oedema, prostatism
Comorbidities, eg orthopnoea, oesophageal reflux, Parkinson's disease
Depression/anxiety—very common and use of an antidepressant will improve sleep much better than a hypnotic
Alcohol dependence
Drugs—corticosteroids, omeprazole, phenytoin, amiodarone, sulfasalazine atorvastatin, ramipril, as well as psychiatric drugs, eg paroxetine, haloperidol, and chlorpromazine can cause insomnia. β-blockers and levodopa cause nightmares
The following non-pharmacological interventions (sleep hygiene) can be tried
Reduce or stop daytime ‘catnapping’
Avoid caffeine, heavy meals and alcohol in the evening (alcohol helps to fall asleep but reduces sleep quality)
Use a bedtime routine
Ensure environment is dark, quiet, comfortable
Relaxation and cognitive behavioural techniques can be useful
Try warm milky drinks
Manage expectations—older people will rarely sleep as much or well as younger people
Drugs
Benzodiazepines (eg temazepam 10mg) are licensed for short term (<4 weeks) management of insomnia and anxiety. They do work well when used correctly (see ‘HOW TO . . . Use benzodiazepines for insomnia’, p.177)
The newer Z-drugs (eg zopiclone, zolpidem, and zaleplon) are only for insomnia. They have shorter half lives and fewer side effects (although zopiclone is still a cause of daytime drowsiness). Overall they are probably slightly superior to benzodiazepines but the same cautions about dependence apply
Other hypnotics (eg chloral hydrate, chlomethiazole, antihistamines) can be toxic, especially in overdose and provide no major advantages
A new class of drugs that act on melatonin pathways may be beneficial but lacks a proven safety record in older people
Tolerance develops after only 4 weeks and benzodiazepines fail to produce a useful sedative effect, however, it only takes this long for dependence to occur. Dependence may be physical (with rebound insomnia, anxiety or even delirium) and/or psychological (the patient believes they will not be able to sleep without tablets). The shorter the half-life the greater the withdrawal effects. Benzodiazepine use has been associated with increased falls, reduced functional status, road traffic accidents, depression, and memory impairment.
Although awareness of these problems have reduced the number of long-term benzodiazepine users, there is still over-prescribing.
Prevention of dependence
Do not use benzodiazepines for mild or non-distressing insomnia—try non-pharmacological measures first
Never prescribe benzodiazepines for more than 4 weeks
Never prescribe benzodiazepines medication at discharge from hospital
All patients/carers should receive warnings about benzodiazepine side effects (especially dependence) and the reason for limiting course length at the outset
GPs should limit repeat prescriptions and audit their practice
Treatment of dependence
Explain and motivate patient/carers
Gradual reduction regimen, eg diazepam by 2–2.5mg every 2 weeks
In difficult cases switch to equivalent dose of diazepam first—long half-life produces milder withdrawal symptoms
Continuing support
Occasionally acute withdrawal is undertaken by mistake (eg drug accidentally not prescribed for a couple of weeks during acute admission with fractured neck of femur). In these cases do not automatically re-start the benzodiazepines and do explain why to the patient or they will just re-start it when they return home
Other sleep disorders
Hypersomnolence
This is excessive daytime sleepiness despite a normal night of sleep. Causes include brain disease (eg dementia, stroke), cardiopulmonary disease (eg cardiac failure, COPD), obstructive sleep apnoea, hypothyroidism, narcolepsy, and sedative drugs.
Restless legs syndrome
A common (10% older people) unpleasant sensation in limbs which increases with drowsiness and is eradicated by movement. Can be associated with limb jerking during sleep with sleep disturbance. Both symptoms respond to benzodiazepines. Dopamine agonists are also used with some success.
Circadian rhythm disorders
Jet lag is the best known but advanced sleep phase syndrome (sleepiness occurs too early in evening but there is early morning wakening) and delayed sleep phase (sleepiness comes too late at night) can occur without such a precipitant. Treat by gradually altering bedtime and bright light therapy when wakefulness desired.
Sleep apnoea in older patients
Obstructive sleep apnoea and central sleep apnoea are very common in older patients and can contribute to daytime sleepiness, accidents and heart failure. Unfortunately periods of apnoea are less likely to be symptomatic than in the young and where symptoms do exist they are often multifactorial so diagnosis and compliance with therapy (non-invasive positive pressure ventilation) can be problematic.
REM sleep behaviour disorder
Dream-enacting behaviour during REM sleep, occurring because of a lack of muscle atonia that usually accompanies REM sleep. About half will go on to develop neurological pathology, eg Parkinson's disease, Lewy body disease. Treatment with benzodiazepines may be successful.
Further reading
