Deletion screening of Sri Lankan Duchenne muscular dystrophy patients using the polymerase chain reaction.

Duchenne muscular dystrophy (DMD) is an X-chromosome-linked myopathy caused by a defect in the DMD gene. Intragenic deletions appear to be the most common gene defect leading to DMD, and the deletion frequency has been estimated to be 66%. Results of this study using a group of 24 DMD patients of Sri Lankan origin employing the technique of multiplex DNA amplification using the polymerase chain reaction indicated a deletion frequency of 62.5%. Eighty per cent of these deletions were localized in a region of the DMD gene regarded as a 'hot spot' for DMD deletions. Our results are in agreement with the results of other studies carried out on Caucasian populations.

Immune activation during cerebellar dysfunction following Plasmodium falciparum malaria.

Evidence for immune activation was investigated in 12 patients with a rare syndrome of self-limiting, delayed onset cerebellar dysfunction following an attack of falciparum malaria which occurred 18-26 d previously. Concentrations of tumour necrosis factor, interleukin 6 and interleukin 2 were all significantly higher in serum samples of patients during cerebellar ataxia than in recovery sera and in the sera of 8 patients who did not develop delayed cerebellar dysfunction following an attack of falciparum malaria. Cytokine concentrations in the cerebrospinal fluid were also significantly higher in ataxic patients than in controls. These findings suggest that immunological mechanisms may play a role in delayed cerebellar dysfunction following falciparum malaria.

Myasthenia gravis in Sri Lanka.

The clinical features and therapeutic aspects of 94 patients with myasthenia gravis seen in the Neurology Institute, General Hospital Colombo, over an eight year period are analysed. The manifestations were similar to that described in the West, but there was a preponderance of male patients, and the ocular myasthenics showed a better response to anticholinesterase medication than described in the world literature. The response to treatment with anticholinesterases, steroids, plasma exchange and thymectomy are assessed.

Tuberous sclerosis presenting as an intraventricular tumour.

We report a case of tuberous sclerosis in an 8 year old girl presenting for the first time with features of raised intracranial pressure due to a large intraventricular tumour. Occurrence of these tumours in children with tuberous sclerosis justifies cranial computerised tomography as a screening procedure to detect these tumours early.

Serum protein binding of antiepileptic drugs in Sri Lankans.

The percentage protein binding of antiepileptic drugs was investigated in epileptic patients (n = 90) undergoing treatment with phenobarbitone, phenytoin and carbamazepine either as a single drug therapy or in different combinations. When administered individually, the percentage (mean +/- SEM) protein binding of phenobarbitone, phenytoin and carbamazepine were 50.84 +/- 7.03, 87.23 +/- 2.98 and 76.80 +/- 6.30 respectively. Combination of phenobarbitone and phenytoin resulted in percentage (mean +/- SEM) protein binding of 51.94 +/- 6.09 for phenobarbitone and 83.54 +/- 7.01 for phenytoin, while the combination of phenobarbitone and carbamazepine resulted in percentage (mean +/- SEM) protein binding of 49.60 +/- 2.59 for phenobarbitone and 79.10 +/- 3.31 for carbamazepine. When phenytoin was given with carbamazepine percentage (mean +/- SEM) protein binding was 87.22 +/- 4.48 for phenytoin and 72.50 +/- 5.92 for carbamazepine.

Non familial juvenile distal spinal muscular atrophy of upper extremity.

An uncommon variety of non familial, juvenile onset, spinal muscular atrophy with asymmetric distal upper extremity affection is described. One hundred and two patients with a one to 14 year follow up are analysed. Spinal muscular atrophies with a distal distribution are rare. However, in the past three decades, previously unrecognised varieties of neurogenic muscular atrophy have been described in Asia (Japan, India, Sri Lanka and Singapore) under a variety of names. These provide interesting data for discussion of Asian neurogenic muscular atrophies with distal affection, in the context of diseases of the motor neuron.

Relationship between dose and serum concentrations of carbamazepine, phenytoin, phenobarbital, and primidone in a Sri Lankan population compared with a European population.

Concentrations of carbamazepine, phenytoin, phenobarbital, and primidone have been measured by high pressure liquid chromatography (HPLC) in serums of 177 Sri Lankan epileptic patients. Relationships between concentrations and dose per kg body weight of these drugs have been compared with those of patients in the Netherlands, using a matching procedure. Although variabilities in dose-concentration ratios were somewhat larger in Sri Lanka than in the Netherlands, no evidence was found of a systematic difference in pharmacokinetics between both populations.

Respiratory failure from severe organophosphate toxicity due to absorption through the skin.

Organophosphates are the most common group of chemicals involved in poisoning in Sri Lanka. Usually, poisoning is by ingestion for suicidal purposes, although accidental poisoning is not uncommon. Poisoning due to absorption through intact or damaged skin is rare. A 32-year-old man was admitted to a peripheral hospital following assault with a 100-ml bottle of insecticide called Monocrotophos, an organophosphate. He had a 2-in. long laceration just above his left eyebrow and there was spilling of the liquid contained in the bottle over his head and face. The liquid was wiped off but the head or face was not washed. After about 3 h the patient developed symptoms and signs of early organophosphate poisoning which were treated with atropine and pralidoxime. On the 3rd day, while on therapy, the patient developed severe weakness of limbs and respiratory distress needing intubation and assisted ventilation. The patient was transferred to the neurology intensive care unit of the General Hospital, Colombo, on the eighth day. His serum potassium levels were low and an ECG showed prominent U waves in all leads. The plasma cholinesterase levels were within 37.5-50% of normal even on the 20th day indicating severe exposure.

The treatment of Guillain-Barré syndrome by modified plasma exchange--a cost effective method for developing countries.

Six patients with the Guillain-Barré syndrome were treated by modified plasma exchange. Five of them showed a rapid improvement which was not consistent with the natural history of the disease. The improvement was assessed by monitoring vital capacity and muscle power, grading the ability to perform motor functions and by the duration of the hospital stay. The method of plasma exchange we used was simpler and cheaper than the conventional method. We recommend the use of our method, especially in developing countries with financial constraints and poor facilities.