Chapter 17: Neurological dilemmas

Harry, a 62-year-old man with a history of hypertension and anxiety, presented one evening because of the acute onset of an amnesic episode. He had driven to collect his two grandchildren from school that afternoon. The children reported that their grandfather appeared his usual self except that he was unable to find his way home. He drove around the neighbourhood for about three hours before eventually locating his house with the help of the children. Upon returning home his family found him confused and unable to remember the events. I found him perplexed and repeatedly asking where he was and how he came to be there. The children said that his driving seemed normal. Harry could not give an account of the day’s events nor could he remember getting up that morning. He could not recall significant recent events such as an overseas holiday. Physical examination was normal.

I had not encountered this amnesic syndrome before so I phoned a consultant neurologist who informed me that it was probably a classic case of transient global amnesia and that the amnesic state should resolve completely leaving only a memory gap for events that occurred during the episode.

I have subsequently encountered two other episodes over the years including that of a 67-year-old GP friend who found himself all confused at an end-of-line suburban railway station on a line quite remote from his usual route home. The initial experience with Harry was a great help in understanding the disorder and thus helped me to confidently counsel subsequent patients.

Many years ago a worried friend contacted me after a flight from London to explain that she had a sudden terrifying experience when she could not speak or use her arms. No one came to her aid because she appeared to be asleep and could not rouse her husband or use the call button. She said that the symptoms gradually abated over the next 15 minutes or so and she felt reasonably normal now. It occurred to me that this was a transient ischaemic attack (TIA) causing the ‘locked in syndrome’ and organised an urgent visit to a neurological unit. Subsequently Bernie has been taking low dose aspirin for 17 years without any further cerebrovascular incidents.

Jenny M, aged 16, a bright schoolgirl and active sportsgirl, was brought along with her somewhat overbearing and overprotective father because she was feeling ‘weak in the arms’; especially around the right arm and wrist where she described a tingling sensation that had been there for the past 24 hours.

Her recent history was that of a mild febrile illness ‘rather like the flu’ a few days beforehand and several hard games of tennis in a tournament that finished the previous day. ‘Doctor—you tell her—she’s overdoing it. All this activity even with the flu. She’s still a growing girl.’

Jenny complained also of headache, nausea and an aching jaw as well as the feeling of weakness in her right arm, which I attributed to soreness following her sporting overload and her viral infection. Reflex testing was equivocal and sensation normal. A tentative diagnosis of post-influenzal weakness aggravated by overuse was made, and father and daughter were reassured. I did wonder about the possibility of cervical spondylosis or carpal tunnel syndrome but thought that her relative youth was against these diagnoses.

Two days later her father rang to inform me that Jenny was confined to bed, her legs were now weak and she was unable to walk properly. ‘[Was] it anything to worry about?’

The home visit

‘Yes, it is something to worry about’, I thought with that sickly feeling that a serious neurological or infectious disorder had been overlooked. Jenny was indeed in trouble. The change was quite dramatic—2 days previously she walked into my surgery looking fit but now she was very weak in all limbs with obvious motor weakness and loss of reflexes. She was also having trouble breathing: ‘Taking a normal deep breath seems impossible’. I tested her peak flow and it was markedly reduced.

DIAGNOSIS AND OUTCOME

Jenny was suffering from Guillain-Barré syndrome (acute post-infective polyneuritis) with respiratory involvement. She was admitted to the infectious-disease hospital where she eventually received assisted ventilation for a few days without developing complete paralysis. She made a complete recovery.

CASE 1

One Sunday afternoon I was startled by the sound of a car hurriedly charging into my driveway and then the almost inhuman sound of a strange high-pitched wailing. A young woman of 34 was in the car in a stuporous state, unable to communicate normally and emitting a haunting, agonised, loud wail. According to her husband they were driving along, enjoying the drive through the hills, when she suddenly grabbed her head and screamed out. Examining this hitherto healthy woman in a car was difficult but I noted that her neck was virtually rigid. We drove her to hospital where I performed a lumbar puncture—evenly blood-stained cerebrospinal fluid (CSF). Subarachnoid haemorrhage! She was transferred to a city hospital and survived, but with a neurological deficit.

CASE 2

One morning I was called urgently to the home of a 43-year-old suburban woman with a long-standing history of severe migraine. She was dead in bed. The previous evening she had developed a sudden severe headache with associated vomiting after getting into bed. Her husband called the locum service. The headache had eased considerably when a young doctor eventually arrived to examine her. He said that she was experiencing a particularly severe migraine attack and gave her an injection of pethidine, which helped considerably and she went to sleep around 10.30 pm—never to awaken.

Andy P, aged 54, presented with a 12-month history of pain in his right thigh. The pain was gradually getting worse to the point where Andy was considering quitting driving his taxi. He claimed that the pain started at ‘the bone’ of the buttock and extended down the back of his thigh to the knee (Figure 17.1). It was aggravated by sitting, relieved by standing and did not bother him at night. There was no inflammatory component to the pain in that it was eased by rest and was absent on waking in the morning. Furthermore, the history did not suggest claudication as a cause.

The only abnormal finding on physical examination was tenderness over the sciatic nerve at the level of the ischial tuberosity. Examination of the lumbosacral spine and regional nervous system was normal. The slump test for dural irritation was negative.

The cause of his sciatica, which is invariably of spinal origin, was puzzling and so an X-ray of his lumbosacral spine was ordered. This was normal. He continued to complain bitterly of the ache and so he was ordered a CT scan, which was also normal.

DIAGNOSIS AND OUTCOME

On review I pondered the possible cause and considered whether pressure from a wallet in his hip pocket could be the cause. After all, he was constantly sitting as part of his occupation. I asked to inspect his wallet, which was ‘hard and bulky’ and contained twelve plastic credit cards. He returned three weeks after a trial of removing the wallet from his right hip pocket to explain that his pain had gradually disappeared.

Terryanne, a 23-year-old housewife, is an epileptic. At our first consultation I found she was being treated with phenytoin and phenobarbitone in dosages that had been juggled over the past two years by the local hospital and other practitioners. Despite this supervision, her clinical equilibrium was fragile. At times she exhibited a variety of neurological symptoms: dizziness, ataxia, paraesthesiae, slurred speech, hyperactivity and ‘funny turns’.

I started a regular check of her phenytoin and phenobarbitone blood levels. Despite her insistence that she always took her tablets exactly as prescribed, Terryanne’s blood levels fluctuated above and below the normal limits.

What did her symptoms indicate?

• High or ‘toxic’ levels of phenytoin

What factors could be responsible for these fluctuations in her blood levels?

• Poor compliance (despite her claims to the contrary)

• Confusion caused by the drugs

• Alcohol and other drugs of self-abuse such as marijuana

• Drug interactions

Phenytoin has been described as the most ‘capricious’ drug in the doctor’s pharmacopoeia, with the potential to react adversely with almost any substance.

Drugs that interfere with metabolism and cause a drop in serum levels include other anticonvulsants (such as phenobarbitone, carbamazepine and clonazepam), alcohol and folic acid. Drugs that raise the serum level include oral anticoagulants, diazepam, propranolol, frusemide, phenothiazines, phenylbutazone, disulfiram and isoniazid.

After checking the drug interaction guide I decided to discontinue phenobarbitone and substitute primidone, which was not implicated. However, the same problems continued. Often her husband would phone me late in the evening with the information that Terryanne was having a ‘funny turn’—acting strangely—and occasionally that she was very agitated.

I suspected alcohol abuse and conducted an investigation befitting Sherlock Holmes, but it drew a blank: alcohol definitely was not involved. I continued probing and during a consultation I learned she had been taking phentermine, prescribed some years ago for weight reduction. I had the answer at last.

Terryanne had developed psychological and physiological dependence on the drug. She had stockpiled it, taking it for anxiety, stress or any manner of ‘disease’ for several days until she felt ‘normal’. Using diazepam as a temporary substitute I weaned her off the phentermine; she does not have strange turns or symptoms any more. Two EEGs have shown normal activity, and primidone has been stopped.

Peter, a 30-year-old computer technician from Sydney, first presented to me for another opinion about his problem of ‘the shakes’ and ‘funny speech’. For the past five years he had noted the gradual onset of shaking of his hands, especially when doing things such as writing or picking up a cup of tea. Over this time his writing became a real problem and he was prone to tumble when walking, especially walking downhill.

His speech was also a problem and his family and friends remarked on how slow and deliberate it had become. Apart from these neurological symptoms he felt quite well. He had consulted three other doctors, including a neurologist, over the previous three years and they could not diagnose his disorder. His family doctor thought he had early Parkinson’s disease. He was not taking any drugs—prescribed or self-administered.

On examination, he had a healthy appearance, an intention-type tremor and mild dysarthria. There was some rigidity of his upper limbs.

The problem confused me, and so I referred Peter to another neurologist for diagnosis and management. He said that he was also puzzled and arranged magnetic resonance imaging of Peter’s brain. This test indicated the presence of demyelination in the area of the basal ganglia. The consultant concluded that he had an ‘exaggerated essential tremor’ and no treatment was warranted.

Other developments in siblings

On review the usual calm and laconic Peter claimed to be very angry with the medical profession for not giving him a satisfactory explanation for the slowly worsening problem and for indulging themselves in an investigation that left him almost $1000 out of pocket. I tried to support him as best I could, and after a year or so he contacted me to say that his 19-year-old sister had been admitted to hospital in Adelaide because of ‘severe swelling of her body’. She was diagnosed as having cirrhosis of the liver. Incredibly, within a few weeks his 26-year-old brother was considered to have a liver disorder.

DIAGNOSIS AND OUTCOME

It was now obvious that Peter and his siblings suffered from the familial disorder of Wilson’s disease (hepatolenticular degeneration). It is an autosomal recessive disorder in which the inherited metabolic defect is associated with the deposition of copper in the liver or central nervous system, or both.

On review we observed the greenish-brown corneal pigmentation (Kayser-Fleischer ring) even with the naked eye, and it was quite outstanding with slit-lamp examination.

Peter has responded extremely well to treatment with penicillamine. His tremor and dysarthria have improved dramatically, but his corneal copper deposits remind us of how we initially ‘missed the boat’. His liver function is good, but his younger siblings still have liver problems. He continues to complain ad nauseam about the lost $1000!

CASE 1: THE CHILD WHO ‘DIED’

A 2-year-old Vietnamese girl presented in dramatic circumstances to the casualty department of a country hospital when I was on duty. She was apnoeic and required manual ventilation by the ambulance officers. They claimed that they went on a call expecting to find a pregnant woman in labour, but instead they found a young Vietnamese woman with her daughter ‘asleep’ in her arms. They noticed that the child was not breathing and thought she was dead, but she had a full pulse. They promptly began artificial ventilation, her colour improved and she remained in a stable condition during the ambulance trip.

On examination in casualty she had a normal colour, a full bounding pulse, normal heart sounds and blood pressure—but no spontaneous respiration. Neurological assessment revealed generalised hypotonia, areflexia (including plantar reflex), fixed dilated pupils and no response to painful stimuli. There were no other abnormal findings in any other system and no evidence of injury. A blood glucose estimation (glucometer) was 6 mmol/L.

The child was promptly intubated and cardiac monitored, and an intravenous line was inserted.

The language barrier made it difficult to obtain an accurate history. However, I was able to ascertain that shortly after eating lunch the child staggered about as though ‘drunk’ and eventually fell to the floor and stopped breathing.

DIAGNOSIS

My initial diagnostic hypotheses included aspiration or an intracerebral catastrophe, but I realised that the clinical information did not support this reasoning. On further questioning of the relatives I learned that for lunch the family had eaten a fish the father had caught off the pier of a Victorian coastal town.

Revised diagnosis

I diagnosed tetrodotoxic fish poisoning due to eating a toadfish (‘toadie’). These poisonous fish are found around the coast of Australia. A quick reference to a text on toxic marine animals (Sutherland, 1983) provided information that the poisoning is characterised by progressive ataxia leading to respiratory paralysis, making it appear that the patient is dead. This did not explain why the parents were spared. Since the toxin is reported to concentrate in the liver and ovaries and only in small amounts in muscle, I considered that the child was served the offal and the parents ate the flesh.

Epilogue

The child was transferred to the intensive care ward of the Royal Children’s Hospital, Melbourne, where she made a full recovery after three days. The prognosis for respiratory arrest in children is apparently excellent.

In Japan the toadfish (fugu) is a delicacy, but it can only be prepared by specially licensed chefs who manage to remove most of the tetrodotoxin from the flesh, although the toxin cannot be removed by washing or by prolonged cooking. Apparently, part of the enjoyment of eating the fish is the tingling sensation felt on the tongue due to small amounts of the toxin. There are several deaths a year in Japan due to ingestion of this fish. Captain Cook almost died in 1774 after sampling a little of the roe and liver of a toadfish in New Caledonia.

CASE 2: A ‘TINGLING’ EXPERIENCE

A 40-year-old businessman, holidaying in Queensland, presented with extreme weakness, exhaustion and strange ‘numb’ and ‘tingling’ sensations around his mouth and in his hands, following an episode of diarrhoea, abdominal pain and vomiting. He gave a fascinating history of how he and his two mates went on a fishing trip near Cairns when they caught some large Spanish mackerel. They said they experienced a strange, cold, tingling feeling in the hands while cleaning the fish.

Five hours after eating one of the fish all three developed what they considered to be a ‘gastric’ attack with diarrhoea and vomiting. After this settled the patient was aware of aching in the joints and muscles as well as the tingling sensations. He said he also experienced a strange burning painful feeling when his hands were placed in cold water. ‘I can’t go swimming in the sea, Doctor—it feels terrible.’ On examination he was afebrile and no specific abnormality could be found.

On review two weeks later he still felt weak and anorexic. He had pruritus of the skin and mild tingling sensations that became worse when exposed to cold factors such as water or ice-cream.

DIAGNOSIS

The patient has ciguatera poisoning due to eating a fish containing ciguatoxin. The problem can occur in all tropical and subtropical sea water to 30° latitude. The differential diagnosis is bacterial food poisoning, but this produces the rapid onset of gastrointestinal symptoms without peripheral neurological effects.