Материал: 100_Cases_in_Clinical_Medicine

ANSWER 85

Although anxiety might produce some of these symptoms and signs, they fit much better with a diagnosis of hyperthyroidism. The neck should be examined carefully and in this case there was a smooth goitre with no bruit over it. Blood tests showed a very low thyroxinestimulating hormone (TSH) level and a high free thyroxine (T4), confirming the diagnosis of hyperthyroidism due to a diffuse toxic goitre (Graves’ disease). Hyperthyroidism may mimic an anxiety neurosis with marked restlessness, irritability and distraction. The most helpful discriminatory symptoms are weight loss despite a normal appetite and preference for cold weather. The most helpful signs are goitre, especially with a bruit audible over it, resting sinus tachycardia or atrial fibrillation, tremor and eye signs. Eye signs which may be present include lid retraction (sclera visible below the upper lid), lid lag, proptosis, oedema of the eyelids, congestion of the conjunctiva and ophthalmoplegia. Atypical presentations of thyrotoxicosis include atrial fibrillation in younger patients, unexplained weight loss, proximal myopathy or a toxic confusional state. The weakness here is suggestive of a proximal myopathy. The very low TSH level indicates a primary thyroid disease rather than overproduction of TSH by the anterior pituitary.

!Common causes of hyperthyroidism

•Diffuse toxic goitre (Graves’ disease)

•Toxic nodular goitre

multinodular goitre (Plummer’s disease) solitary toxic adenoma

• Over-replacement with thyroxine

Blood should be sent for thyroid-stimulating immunoglobulin which will be detected in patients with Graves’ disease. Medical treatment for thyrotoxicosis involves the use of the antithyroid drugs carbimazole or propylthiouracil. These are given for 12–18 months but there is a 50 per cent chance of disease recurrence on stopping the drugs. If this happens radioiodine or surgery is indicated. Beta-blockers can be used to rapidly improve the symptoms of sympathetic overactivity (tachycardia, tremor) while waiting for the antithyroid drugs to act. Radio-iodine is effective but there is a high incidence of late hypothyroidism. Surgery is indicated if medical treatment fails, or if the gland is large and compressing surrounding structures. In severe exophthalmos there is a risk of corneal damage and ophthalmological advice should be sought. High-dose steroids, lateral tarsorrhaphy or orbital decompression may be needed.

KEY POINTS

•Thyrotoxicosis may be difficult to differentiate from an anxiety state.

•The commonest causes of hyperthyroidism are Graves’ disease or a toxic nodular goitre.

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CASE 86: WEAKNESS OF THE LEGS

History

A 48-year-old man presents to the emergency department with weakness of his legs. Four weeks earlier he had symptoms of an upper respiratory tract infection. Four days before admission he had a feeling that there was something wrong in his feet, and 3 days before admission he started to develop some difficulty in walking. Now he says that he is hardly able to move his legs below his knees. Both feet have also become painful over the last day or so. His bowels and bladder are functioning normally. He has no significant past medical history. He neither smokes nor drinks alcohol and is taking no medication.

Examination

He looks well but is anxious. His pulse rate is 104/min, and blood pressure 162/98 mmHg. His jugular venous pressure is not raised and examination of his heart, respiratory and abdominal systems is normal. Neurological examination shows grade 1/5 power below his knees and 2/5 power for hip flexion/extension. The tone in his legs is reduced. Knee and ankle reflex jerks are absent. There is impaired pinprick sensation up to the thighs and reduced joint position sense and vibration sense in the ankles. Neurological examination of his arms is normal.

INVESTIGATIONS

Initial haematology and biochemistry results are normal.

A lumbar puncture is performed with the following results:

Questions

•What is the diagnosis?

•What are the major differential diagnoses?

•How would you manage this patient?

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ANSWER 86

The most marked feature is the loss of power. The reduced tone and absent reflexes indicate that this is a lower motor neurone lesion. The sensory disturbance is less severe and he has a sensory level around L2/3. This man has Guillain–Barré syndrome (acute idiopathic inflammatory polyneuropathy). This disorder is a polyneuropathy which develops usually over 2–3 weeks, but sometimes more rapidly. It commonly follows a viral infection or Campylobacter gastroenteritis, and a fever is common. It predominantly causes a motor neuropathy which can either have a proximal, distal or generalized distribution. Distal paraesthesiae and sensory loss are common. Reflexes are lost early. Cranial and bulbar nerve paralysis may occur and can cause respiratory failure. The CSF protein is usually raised, but the cell count is usually normal, although there may be a mild lymphocytosis. The disorder is probably due to a cell-mediated delayed hypersensitivity reaction causing myelin to be stripped off the axons by mononuclear cells.

!Differential diagnoses of motor neuropathy

•Guillain–Barré syndrome

•Lead poisoning

•Diphtheria

•Charcot–Marie–Tooth disease (hereditary motor and sensory neuropathy)

•Poliomyelitis

An acute-onset neuropathy suggests:

•Guillain–Barré syndrome

•porphyria

•malignancy

•some toxic neuropathies

•diphtheria

•botulism.

This patient should be referred to a neurologist for further investigation and management. In this patient who presents with weakness and sensory signs, it is important to make sure there is no evidence of spinal cord compression or multiple sclerosis. However, these would tend to cause hypertonia, hyper-reflexia and a more distinct sensory level. A magnetic resonance imaging (MRI) scan of the brain and spinal cord should therefore be considered. Nerve-conduction studies will confirm a neuropathy. He should be treated either with plasma exchange or intravenous immunoglobulin. His respiratory function should be monitored with daily spirometry, and mechanical ventilation may be necessary. Most patients recover over a period of several weeks.

KEY POINTS

•Guillain–Barré syndrome presents with predominantly a motor neuropathy although sensory symptoms are usually present.

•There is often a history of an infective illness in the previous 3 weeks, often

Campylobacter jejuni.

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CASE 87: RECURRENT FALLS

History

An 85-year-old man is admitted to hospital because of a fall in which he has sustained a mild facial laceration. In the history it becomes evident that he has had around eight falls over the last 3 months. He says that the falls have occurred in the morning on most occasions but have occasionally occurred in the afternoon. He does not think that he has lost consciousness although he does remember a sensation of dizziness with the falls. He says that the falls have not been associated with any chest pain or palpitations. He does not remember tripping or any other mechanical trigger to the falls. He seems to return to normal within a few minutes of the fall. On two or three occasions he has hurt his knees on falling, and on one other occasion he hit his head. He lives alone and there have been no witnesses of any of the falls.

He smokes five cigarettes a day and does not drink. He has an occasional cough with some white sputum but he cannot remember whether he was coughing at the time of any of the falls. He was diagnosed as having hypertension at a routine well man clinic 4 years ago, and has been on treatment with a diuretic, bendrofluazide and doxazosin, for this. The blood pressure has been checked in the surgery on three or four occasions and he was told that it has been well controlled. He was found to have a high fasting blood sugar 6 months before and had been advised a diabetic diet. There is no relevant family history. He worked as a messenger until he retired at the age of 70 years.

Examination

He looks well. His pulse is 90/min and irregular. The blood pressure is 134/84 mmHg. The heart sounds are normal and there is nothing abnormal to find on examination of the respiratory system or gastrointestinal system. There are no significant hypertensive changes in the fundi. In the nervous system, there is a little loss of sensation to light touch in the toes, but no other abnormalities.

INVESTIGATIONS

Results of an electrocardiogram are shown in Fig. 87.1.

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