16 Neurology

Automatic responses. The reflex arc goes from the stimulus via a sensory nerve to the spinal cord and then back along a motor nerve to cause muscle contraction, without brain involvement.

See Table 16.2. Record whether absent, present with reinforcement, normal, or brisk ± clonus.

Implies a breach in the reflex arc at:

Implies lack of higher control—an upper motor neurone lesion, e.g. post-stroke.

Rhythmic involuntary muscle contraction due to abrupt tendon stretching, e.g. by dorsiflexing the ankle—associated with an UMN lesion.

Method of accentuating reflexes. Use if a reflex seems absent. Ask patients to clench their teeth (to reinforce upper limb reflexes) or clench their hands and pull in opposite directions (to accentuate lower limb reflexes). This effect only lasts ~1s, so ask patients to perform the manoeuvre simultaneously with the tap from the tendon hammer.

See Table 16.1

Test proximal muscle power by asking the patient to sit from lying, pull you towards him/herself, or rise from squatting.

Table 16.3 summarizes cranial nerve lesions and their causes. Figure 16.1 shows the cutaneous innervation of the head and neck. Cranial nerves may be affected at any point from the nerve nucleus within the brainstem to the point of innervation. Think systematically about the level of the lesion. Potential sites:

Any cranial nerve may be affected by DM, MS, tumours, sarcoid, vasculitis or syphilis and >1 nerve may be affected by a lesion. Refer according to cause to ENT, ophthalmology, or neurology.

See Figure 16.2 ( p. 540) and Figure 16.3 ( p. 541).

Lesions of individual peripheral (including cranial) nerves. Causes: trauma, compression, DM, leprosy. If >1 peripheral nerve is involved, the term mononeuritis multiplex is used. Causes: DM, sarcoid, cancer, PAN, amyloid, leprosy.

See Table 16.4.

Facial palsy without other signs. Unknown cause—possibly viral. Peak age: 10–40y. ♂ = ♀. Lifetime incidence: ~1:65. Affects left and right side of the face equally often. Usually sudden onset—may be preceded by pain around the ear. Other possible symptoms: facial numbness; ↓ noise tolerance; disturbed taste on the anterior part of the tongue.

~70% recover completely; 13% have insignificant sequelae; the remainder have permanent deficit. 85% improve in <3wk—reassure. Give prednisolone (25mg bd for 10d) if <72h after onset of symptoms^R. Protect eye—tape lid shut and pad at night; glasses in the day ± artificial tears if drying. Refer:

C. Bell (1774–1842)—Scottish anatomist and surgeon

Severe pain in the ear precedes facial nerve palsy. Zoster vesicles appear around the ear, in the external ear canal, on the soft palate, and in the tonsillar fossa. Often accompanied by deafness ± vertigo which are slow to resolve and may result in permanent deficit. Pain usually abates after 48h but post-herpetic neuralgia can be a problem. If detected <24h after the rash appears, treatment with antivirals (e.g. aciclovir 800mg 5x/d for 1 wk) may be effective.

J. Ramsay Hunt (1872–1937)—US neurologist.

p. 498

Postural hypotension (dizziness or syncope on standing, after exercise or a large meal), impotence, inability to sweat, vomiting and dysphagia, diarrhoea or constipation, urinary retention or incontinence, Horner’s syndrome ( p. 300). Check BP lying and standing—a postural drop of ≥30/15mmHg is abnormal. Causes:

Treat any underlying cause. Advise patients to stand slowly, raise the head of the bed at night, eat little and often, and ↓ carbohydrate and alcohol intake. Fludrocortisone (0.1mg/d, increasing prn–unlicensed) may help those most severely affected. An alternative (also unlicensed) is midodrine. Refer if diagnosis is unclear or simple measures are ineffective.

p. 542

Generalized disorder of peripheral nerves, including cranial and autonomic nerves. Distribution is bilateral, symmetrical, and widespread.

Presents as numbness, tingling, or burning sensation often affecting the extremities first (glove and stocking distribution) or causing clumsiness handling fine objects (e.g. needle).

Presents as progressive weakness or clumsiness of hands, stumbling/falls on walking, respiratory difficulty (can progress rapidly). Examination: wasting and weakness most marked distally; reflexes are ↓ or absent.

See Table 16.5.

Exclude common causes—check blood glucose, FBC, ESR, U&E, Cr and eGFR, LFTs, TFTs, plasma B₁₂, autoimmune profile, syphilis serology.

Treat cause if possible. Involve physiotherapists and OT. If sensory neuropathy care of the feet is important to minimize trauma and consequent disability. Refer if a cause is not found.

Presents at puberty or in early adult life and begins with foot drop and weak legs. The peroneal muscles are the first to atrophy. The disease spreads to the hands then arms. Sensation and reflexes are also ↓. Unknown cause. Once diagnosis is confirmed treatment is supportive.

J.M. Charcot (1825–93) and P. Marie (1853–1940)—French neurologists; H.H. Tooth (1856–1925)—English neurologist.

Develops within a few weeks of surgery, flu vaccination or infection (URTI, flu, VZ, HSV, CMV, EBV, Campylobacter, Mycoplasma). In 40% no precipitating event is found.

Presents with ascending motor neuropathy which may advance fast. Proximal muscles are more affected than distal muscles. Trunk, respiratory muscles, and cranial nerves are commonly affected.

If suspected admit immediately to hospital as an emergency. Ventilation on ITU is frequently required; 85% make a complete or near-complete recovery; 10% are unable to walk alone at 1y; mortality is 10%.

C. Guillain (1876–1961) and J.A. Barré (1880–1967)—French neurologists.

p. 579

Rare autosomal recessive disorder which presents in the second decade or later with sensorimotor polyneuropathy, ataxia, visual, and/or hearing problems. Treatment involves dietary restriction (avoidance of chlorophyll-containing foods) and plasmapheresis.

S. Refsum (1907–1991)—Norwegian physician.

Gait means manner of walking. Abnormal gait can give clues to the underlying problem.

Normal gait is interrupted by abnormal movements, e.g. choreiform movements, athetoid movements or hemiballismus. May indicate underlying neurological problem, e.g. cerebral palsy, Huntington’s chorea.

Gait adjusts to try to minimize pain in a joint—usually OA hip. The patient leans towards the affected side and takes a rapid step on that side followed by a slower step on the contralateral side—check Trendelenburg’s sign ( p. 488).

Apart from alcohol, the other major cause of drunken gait is a cerebellar lesion. Features:

Patients trip frequently or walk with a high stepping gait. On examination, patients are unable to walk on their heels and cannot dorsiflex their foot. Check ankle jerk. Causes:

Style of walking seen in patients with UMN lesions. Features:

Marked unsteadiness—the feet appear stuck to the floor causing a wide-based, shuffling gait.

Seen in patients with Parkinson’s disease and other causes of parkinsonism. Features:

As the name implies, the patient walks as if his/her legs were like a pair of scissors. Associated with spastic paraplegia

Loss of proprioception due to peripheral neuropathy or spinal cord disease (e.g. cervical spondylosis, MS, syphilis, combined degeneration of the cord) results in an ataxic gait similar to that seen with cerebellar disease. Check Romberg’s test. Features:

Typically seen in patients with proximal myopathy, e.g. due to muscular dystrophy. Other causes: pregnancy, congenital dislocation of the hip. Features:

p. 544

Painful muscle spasm. Common—especially at night and after exercise. Rarely associated with disease—salt depletion, muscle ischaemia, myopathy. Forearm cramps suggest motor neurone disease. Night cramps in the elderly may respond to quinine bisulphate 300mg nocte twice weekly.

Prolonged muscle contraction producing abnormal postures or repetitive movements.

Involuntary chewing and grimacing movements, resulting from long-term neuroleptic treatment (metoclopramide and prochlorperazine are also possible causes). Withdraw neuroleptic—if no improvement after 3–6mo consider tetrabenazine 25–50mg tds po.

The Dystonia Society   020 7793 3650  www.dystonia.org.uk

Sudden, involuntary focal or general jerks. May be normal, especially if occurs when falling asleep. Other causes:

If needed treat with sodium valproate or clonazepam.

Impairment of performance of complex movements despite preservation of ability to perform their individual components. Test by asking the patient to perform everyday tasks (e.g. ask to dress/undress), copy complex hand movements and do familiar sequences of movements (e.g. ‘head, shoulders, knees, and toes’).

p. 916

Most common causes are stroke or space-occupying lesion. Involve rehabilitation services and OT.

Intermittent lapses of an assumed posture. May involve arms, neck, tongue, jaw, and eyelids. Usually bilateral, absent at rest, and asynchronous on each side. Causes: liver failure (flapping tremor), heart failure, respiratory failure, renal failure, hypoglycaemia, barbiturate intoxication.

Slow, confluent, often rhythmic, purposeless movements of hands, tongue, fingers, or face. Causes: cerebral palsy, kernicterus.

Non-rhythmic, jerky, purposeless movements (especially hands), with voluntary movements possible in between. Most common causes: cerebral palsy, Huntington’s chorea, Sydenham’s chorea.

Large-amplitude, involuntary flinging movements of limbs. May occur after stroke, in Huntington’s disease or with high doses of levodopa for PD.

Brief, repeated, and stereotyped movements which are able to be suppressed voluntarily for a while. Common in children and usually resolve spontaneously. Consider clonazepam or clonidine if tics are severe.

p. 911

p. 936

Disorder of rhythm and fluency of speech in which syllables, words, or phrases are repeated. ♂: ♀ ≈4:1. Cause: unknown. Can result in stress and embarrassment.

Difficulty with articulation due to incoordination or weakness of the musculature of speech. Language is normal. Ask to repeat ‘baby hippopotamus’ or ‘British constitution’. Treat the cause if possible otherwise support with speech therapy and aids to communication. Causes: see Table 16.6.

Impairment of language due to brain damage to the dominant hemisphere. The left hemisphere is dominant for 99% of right-handed people and 60% of left-handers. In most cases, due to stroke or brain tumour. Rarely due to head injury or dementia. Assessment and classification: see Table 16.7. Mixed pictures are common. Treatment:

Autoimmune disease. Antibodies to the acetylcholine receptor cause a deficit of receptors at the neuromuscular junction → muscle weakness. Antibodies are detectable in 90%. ♀:♂ ≈2:1. Associated with thymic tumours and other autoimmune disease, e.g. RA, SLE, hyperthyroidism. Generally follows a relapsing or slowly progressive course. If thymoma present, 5y survival ≈ 30%.

Young adults with easy fatigability of muscles. Commonly affected muscles are the:

Weakness is exacerbated by pregnancy, infection, drugs (e.g. β-blockers, opiates, tetracycline, quinine), climate change, emotion, and exercise.

If suspected refer for confirmation by a neurologist and specialist treatment. Treated with:

Occurs in association with small cell carcinoma of the lung or rarely autoimmune disease. Differs from myasthenia gravis by the tendency to hyporeflexia. Autonomic involvement is common. Proximal limb muscles/trunk are most commonly involved. Specialist treatment is essential.

Blackouts, faints, and funny turns are all common presentations to general practice. The major questions which should be asked seeing an individual who has had a funny turn are:

A good history from the patient and ideally from a witness is essential in the correct diagnosis. Ask:

Complete general and neurological examination. Particularly check for:

p. 896

p. 574

Abrupt and transient loss of consciousness due to a sudden ↓ in cerebral perfusion. Common—prevalence ~6% adults. It has many causes, ranging from benign (vasovagal syncope) to fatal (sustained ventricular tachycardia); the prognosis depends on the cause.

A typical attack takes the following pattern:

Is the term applied to a less severe attack with partial loss of consciousness and a near fall.

Common. Peripheral vasodilatation, bradycardia, and venous pooling → postural hypotension. Often cause is unclear, though ♀ > ♂. Known precipitants: fright (e.g. during venesection) or emotion. Exclude other reasons for loss of consciousness. No treatment needed—reassure.

Distinguish between true vertigo (the illusion of rotatory movement—the room spinning) and a feeling of unsteadiness or light-headedness:

p. 1120

Usually history is diagnostic but occasionally, seizures of temporal lobe origin may have similar symptomatology.

Affects patients with DM—particularly those taking insulin or oral hypoglycaemic agents. Produces autonomic changes, e.g. pallor, sweating and tachycardia, and behavioural changes (confusion, altered personality). If action is not taken to ↑ blood sugar, coma ± fitting ensues— p. 1100.

(e.g hallucinations— p. 988).

Common presenting complaint. The skill lies in deciding which headaches are benign, needing no intervention, and which require action.

In acute, severe headache, examine for fever and purpuric skin rash. In all cases check BP, brief neurological examination including fundi, visual acuity, and gait, palpation of the temporal region/sinuses for tenderness, and examination of the neck. In young children, measure head circumference and plot on a centile chart.

Often not needed. ESR if temporal arteritis is suspected.

See Table 16.8. ↑ BP may cause acute or chronic headache. Direct treatment at the cause.

Headache, stiff neck, and photophobia. Associated with meningitis. May also be seen with encephalitis and SAH.

Migraine affects 15% of the UK population. ♂:♀ ≈1:3. One in three experiences significant disability. Caused by disturbance of cerebral blood flow under the influence of 5HT.

Occurs with or without headache. Symptoms arise over ≥5min and last 5–60min before resolving completely. Diagnose if:

Consider referral for further investigation if: motor weakness; double vision; visual symptoms affecting only one eye; poor balance or ↓ level of consciousness.

Moderate to severe unilateral or bilateral throbbing/pulsating headache that lasts 4–72h (1–72h in children) and prevents usual activities. May occur with or without aura and be associated with nausea/vomiting ± ↑ sensitivity to light/noise.

p. 552

Repeat symptomatic treatments within their dose limitations—pre-emptively if recurrence is usual/expected. If using triptans, a second dose may be effective, but repeated dosing can cause rebound headache. Naratriptan and eletriptan are associated with relatively low recurrence rates.

Aims to control symptoms and minimize impact on the patient’s life. Cure is not a realistic aim.

Half have a trigger for their migraine. Consider:

Assessment scales, e.g Migraine Disability Assessment Score (MIDAS—see Box 16.1   p. 585), can be useful in assessing impact of symptoms on daily life and monitoring response to treatment.

Reassure. Instruct about management of acute attacks. A diary can be used to identify trigger factors, assess headache frequency, severity, medication usage/overusage, and response to treatment. Avoid trigger factors where possible. Give advice on relaxation techniques and stress management. Do not offer CHC to women with migraine, especially if aura ( p. 753).

Consider if ≥4 attacks/mo or severe attacks. ↓ attacks by ~50%. Try a drug for 2mo before deeming it ineffective. If effective, continue for 6mo then review to consider ↓ dose slowly before stopping.

Riboflavin 400mg od may ↓ frequency/intensity of headaches^N; feverfew 200mg daily may↓ symptoms after 6wk use^C.

Suspect if migraine occurs from 2d before to 3d after start of period on at least 2 out of 3 consecutive months (use headache diary). If predictable menstrual-related migraine that does not respond to standard acute treatment, consider frovatriptan (2.5mg bd) or zolmitriptan (2.5 mg bd/tds) on the days that migraine is expected.

p. 552

p. 554

Prevalence 4%. Defined as any headache that occurs >15d/mo. Common causes: tension-type headache, cervicogenic headache ( p. 474), medication-overuse headache, migraine, errors of refraction (usually headache is mild, frontal, in the eyes themselves, and absent on waking). Treat the cause (may be >1).

Associated with stress and anxiety and/or functional or structural abnormalities of the head or neck. Prevalence ≈2%. ♀:♂ ≈2:1. Symptoms begin aged <10y in 15% patients. Prevalence ↓ with age. Family history of similar headaches is common (40%), but twin studies do not suggest a genetic basis. Distinguish between episodic and chronic tension-type headache:

In both cases pain:

Reassure no serious underlying pathology. Try measures to alleviate stress—relaxation; massage; yoga; exercise. Treat musculoskeletal symptoms with physiotherapy.

Analgesics are of limited value and might make matters worse (see Medication-overuse headache).

Extremely painful headaches focussed around 1 eye with associated autonomic symptoms on that side (drooping eyelid, constricted pupil, red watery eye, runny or blocked nose, forehead sweating). Rare <20y of age. ♂:♀ ≈6:1. More common in smokers. Pain lasts 15–180min and occurs from 1x every 2d to 8x/day. Recurrences affect the same side. Onset is often predictable (1–2h after falling asleep; after alcohol). 2 patterns:

Refer for specialist advice/neuroimaging for first bout of cluster headache. Drug treatments:

Persistent headache in patients with other causes of pain who are overusing analgesics. Affects 1 in 50 adults; ♀:♂ ≈5:1. Consider if headache develops/worsens when taking analgesic medication for ≥3mo. Implicated drugs include:

Explain the condition to the patient. Advise stopping overused medication abruptly for at least 1mo. Provide follow-up and support over 4–8wk; warn that symptoms may worsen initially (day 3–7) before improving. Review treatment of any underlying problem (e.g. migraine or chronic musculoskeletal pain). Consider specialist referral if taking strong opioids or recurrent, failed attempts to stop medication overuse.

Treat the cause. Common causes include: trigeminal neuralgia; temporomandibular joint disorders; dental disorders; sinusitis; migrainous neuralgia; shingles and post-herpetic neuralgia. No cause is found in many patients—it is then termed atypical facial pain. Atypical facial pain may respond to simple analgesia with paracetamol or NSAID. If this fails, try nerve painkillers, e.g. amitriptyline 10–75mg nocte. If troublesome symptoms, refer to ENT, maxillofacial surgery, or neurology.

Paroxysms of intense stabbing, burning, or ‘electric shock’ type pain, lasting seconds to minutes in the trigeminal (V) nerve distribution; 96% unilateral. Mandibular/maxillary > ophthalmic division. Between attacks there are no symptoms. Frequency of attacks ranges from hundreds/d to remissions lasting years. Pain may be provoked by movement of the face (talking, eating, laughing) or touching the skin (shaving, washing). Can occur at any age but more common >50y. ♀ > ♂. Unknown cause but associated with MS.

Spontaneous remission may occur.

<50y; neurological deficit between attacks; treatment with first-line agents fails—specialist options include lamotrigine, duloxetine, baclofen, phenytoin, or surgical intervention.

Raised intracranial pressure (↑ ICP) usually presents with increasing headache associated with drowsiness, listlessness, vomiting, focal neurology, and/or seizures. Causes include: 1° or 2° tumours, head injury, intracranial haemorrhage, hydrocephalus, meningitis, encephalitis, brain abscess, and cerebral oedema (2° to tumour, trauma, infection, ischaemia).

Symptoms/signs of a space-occupying lesion, but none is found. Usually occurs in young, obese women. Cause unknown. Treated with repeat lumbar puncture, ventriculo-peritoneal shunt, diuretics, or dexamethasone. Usually resolves—but 10% recur later.

May be single or multiple. Organisms reach the brain via the blood stream, direct implantation, or local extension from adjacent sites (e.g. sinusitis). Presents with ↑ ICP, focal neurological signs, systemic effects of infection, and/or local effects due to the cause. Usually, features develop over 2–3 wk—occasionally, more slowly; in the immunosuppressed, onset is rapid. If suspected, admit as an emergency. Treatment is with IV antibiotics ± surgical drainage. Mortality is 20–30%. 50% of survivors have long-term neurological deficit; 30% epilepsy.

<1% of patients with headache have a brain tumour.

Stroke, MS, head injury, vasculitis, encephalitis, Todd’s palsy ( p. 574), metabolic/electrolyte disturbance, other causes of space-occupying lesion—aneurysm, abscess, chronic subdural haematoma, granuloma, cyst.

Gliomas all have <50% 5y survival. Depending on site, meningiomas and haemangioblastomas have better prognosis.

Dilatation of the cerebral ventricles and accumulation of CSF. May be:

In infants presents with macrocephaly ( p. 893); convulsions; developmental delay; and/or spasticity. In adults presents with ↑ ICP. Refer for urgent neurological assessment. All patients with a CSF shunt should have pneumococcal vaccination.

p. 562

Spontaneous bleeding into the subarachnoid space. Incidence 15/100,000. ♀ > ♂. Peak age 35–65y. Frequently fatal. Causes:

Smoking, alcohol, ↑ BP, less common pre-menopause. Berry aneurysms may run in families and are associated with polycystic kidneys, coarctation of the aorta, and Ehlers–Danlos syndrome.

May be nothing to find initially. Neck stiffness takes 6h to develop. In later stages:

If suspected admit immediately as a medical emergency. Only 1 in 4 admitted with suspected SAH turn out to have one. In most no cause for the headache is found.

Bleeding is from bridging veins between cortex and venous sinuses, resulting in accumulation of blood between dura and arachnoid. Causes: trauma (may be trivial); idiopathic.

Age, alcohol, falls, epilepsy, anticoagulant therapy.

Often insidious and history may go back several weeks:

Stroke, cerebral tumour, dementia.

If suspected, admit as a medical emergency for further investigation. Evacuation of clot is possible even in very elderly patients and often results in full recovery.

Blood accumulated between the dura and bone of the skull. Usually occurs after head injury.

Deterioration of level of consciousness after head injury that initially produced no loss of consciousness or after initial post-injury drowsiness has resolved. This ‘lucid’ interval may last anything from a few hours to a few days. May be accompanied by worsening headache, vomiting, confusion ± focal neurological signs.

If suspected, admit as an emergency for further investigation. Early evacuation of clot carries excellent prognosis. Outlook is less good if coma pre-op.

Clinical syndrome typified by rapidly developing signs of focal or global disturbance of cerebral functions, lasting >24h or leading to death, with no apparent causes other than of vascular origin. Common and devastating condition—most common cause of adult disability in the UK. Half of all strokes occur in people >70y.