Application of DNA-based tests for diagnosis of spinal muscular atrophy in Saudi Arabia

We examined the deletion of the survival motor neuron (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes in patients with spinal muscular atrophy (SMA) using polymerase chain reaction followed by restriction site assay methods. The study included 16 Saudi patients (9 SMA type I and 7 SMA type II) and 6 healthy Saudi volunteers. The homozygous deletions of exons 7 and 8 of the telomeric SMN gene, and exon 5 of the NAIP gene were found in all SMA type I patients. Exons 7 and 8 of telomeric SMN were deleted in all SMA type II patients. However, exon 5 of NAIP was deleted in three of the seven cases. All control volunteers and all family members of the patients had normal SMN and NAIP. The incidence of NAIP deletion was higher in the more severe SMA cases and the dual deletion of the SMN and NAIP genes was more common in Saudi SMA type I patients compared with patients of other ethnic groups.

Motor terminal latency index in carpal tunnel syndrome

We determined the motor terminal latency index (MTLI) of the median nerve across the carpal tunnel in 41 upper extremities of 31 patients with carpal tunnel syndrome. Changes in motor nerve conduction velocity (MNCV), motor terminal latency (MTL), sensory action potential and the amplitude of the compound muscle action potential recorded from the abductor pollicis brevis muscle were all suggestive of proximal and distal segment involvement of the nerve across the carpal tunnel. There was no correlation between forearm MNCV and MTL (r = 0.40), although MTLI was correlated with MTL (r = 0.67) but not with MNCV, indicating a disproportionate conduction across the carpal tunnel.

Risk factors of stroke at high and low altitude areas in Saudi Arabia

BACKGROUND

The epidemiology of stroke at different geographical locations in the Kingdom of Saudi Arabia has not been adequately investigated.

METHODS

In this study, clinical types and risk factors of stroke were compared among patients at low-altitude (Riyadh, 620 m) and high-altitude (Al Baha > 2000 m) areas using a case-control study design. One-hundred ninety recently diagnosed cases (109 from Riyadh and 81 from Al Baha) were verified and subjects were interviewed. An equal number of age- and sex-matched controls from the corresponding areas were also interviewed using a specific standard questionnaire.

RESULTS

The frequency of thrombotic stroke at high altitude was 93.4% as compared to 79.3% at low altitude (P < 0.05). The odds ratios (OR) for the different risk factors at high and low altitudes, respectively, were: hypertension 4.4 and 2.1; diabetes mellitus: 2.7 and 1.9; ischemic heart disease (IHD): 2.4 and 1.9; atrial fibrillation: 3.9 and 3.3, and smoking: 2.3 and 2.5. The mean hematocrit values were 45.3% at high altitude and 41.0% for low altitude patients (P < 0.001) and its association with stroke at high altitude remained significant even after adjusting for age, gender and occupation.

CONCLUSIONS

The study's finding of an increased frequency of thrombotic stroke at high altitude was explained by increased hematocrit which might have caused this in conjunction with other factors such as hypertension and IHD. Larger studies are recommended for better clarification of interaction between high altitude and other established risk factors not included in this study, such as sickle cell anemia and congenital heart diseases in young patients.

Stroke register: experience from the eastern province of Saudi Arabia

A stroke registry was established in the Eastern Province of Saudi Arabia with an estimated population of 750,000 inhabitants of whom 545,000 are Saudi citizens. The register started in July 1989 and ended in July 1993. The Gulf war led to its interruption from August 1990 to August 1991. Four hundred eighty-eight cases (314 males, 174 females) of first-ever strokes affecting Saudi nationals were registered over the 3-year period. The crude incidence rate for first-ever strokes was 29.8/100,000/year (95% CI: 25.2-34.3/100,000 year). When standardized to the 1976 US population, it rose up to 125.8/100,000/year. Ischemic strokes (69%) predominated as in other studies but subarachnoid hemorrhage (SAH) was extremely rare (1.4%). The important risk factors were: systemic hypertension (38%), diabetes mellitus (37%), heart disease (27%), smoking (19%) and family history of stroke (14%). Previous transient ischemic attacks (3%) and carotid bruits (1%) were uncommon. The 30-day case fatality rate was 15%. The study showed that the age-adjusted stroke incidence rate for Saudis in this region is lower than the rates reported in developed countries but within the range reported worldwide. The pattern of stroke in Saudi Arabia is not different from that reported in other communities with the exception of the low incidence of SAH. The risk factors are similar to findings in other studies except for the high frequency of diabetes mellitus in our cases. The lower mortality rate was probably due to the younger age of the population and the availability of free medical services for management of cases.

Cerebral venous thrombosis in adults. A study of 40 cases from Saudi Arabia

BACKGROUND AND PURPOSE

We undertook this study to determine the frequency, clinical patterns, and etiologies of cerebral venous thrombosis in a Middle Eastern country.

METHODS

Records of all adults patients admitted with an angiographically documented diagnosis of cerebral venous thrombosis from 1985 through 1994 in two major hospitals of Riyadh, Saudi Arabia, were reviewed.

RESULTS

Forty patients (20 men, 20 women) aged 16 to 40 years were identified. Hospital frequency was 7 per 100,000 patients, and the relative frequency against arterial strokes was 1:62.5. Nineteen cases (47%) had a clinical picture of pseudotumor cerebri. Behçet's disease was the cause in 10 cases (25%). Other causes included antiphospholipid antibodies in 4, protein S deficiency in 3, intracranial tumors in 3, systemic lupus erythematosus in 3, infections in 3, antithrombin III deficiency in 2, postpartum in 1, and oral contraceptives in 1.

CONCLUSIONS

Cerebral venous thrombosis in adults is not uncommon in Saudi Arabia. Behçet's disease is the single most common etiology. Infection is no longer an important cause, whereas "new" coagulation disorders are common. Patients with a pseudotumor cerebri syndrome should undergo angiography or brain MRI before being labeled idiopathic.

Perceptions of the educational contract among Saudi residents and western staff physicians in Saudi Arabia

BACKGROUND

Approved residency programs are increasingly being set up in Saudi Arabia and require that many Western staff physicians be rapidly deployed.

METHOD

A non-university hospital in Saudi Arabia that employs several expatriate staff physicians undertook focused program evaluations of residencies in four disciplines in 1991 and again in 1992. Interviews, written comments, and questionnaires were used to collect residents' ratings of their training and clinical instructors and the residents' and staff physicians' perceptions regarding their educational contract, i.e., the personal agreement between teachers and learners. According to educational contract theory, clinical teachers adopt three basic roles (expert, model, or facilitator), as do residents (dependent, competitive, or participant). Chi-square with Yates' correction was used for statistical analysis.

RESULTS

All 137 possible responses were returned (72 in 1991 and 65 in 1992). In 1991 the residents and staff physicians perceived the Saudi residents as mostly dependent, and 71% of the residents thought that the staff physicians were experts or models. This percentage conflicted with the staff physicians' own perceptions of their role as facilitators (46%). In 1992 the staff physicians increasingly perceived the residents as competitive (from 5% in 1991 to 10% in 1992), and the residents increasingly perceived the staff physicians to be facilitators (from 28% to 50%).

CONCLUSION

The study compelled the staff physicians and residents to reexamine their perceptions of the educational contract between them. The resultant tendency toward convergence of perception was instructive and mutually beneficial.

Pattern of subarachnoid haemorrhage in Saudi Arabia

It has often been claimed that subarachnoid haemorrhage (SAH) is a rare condition in the Middle East. A 7-1/2-year retrospective study was undertaken to substantiate or disprove this claim. It was found that although the condition is less common than the global average, it was not as rare as previously supposed. The pattern of distribution throughout the population, in terms of sex, was significantly different. The possible reasons for this are discussed.

Cerebral palsy in Saudi Arabia: a case-control study of risk factors

There is increasing evidence that cerebral palsy (CP) in developed countries results mainly from antenatal factors, whereas reports from developing countries suggest that perinatal and postnatal factors may be more important because of less than optimal delivery conditions. The authors studied 103 Saudi children with CP and compared their antecedent factors with those of a control group. The major risk factors identified were a history of CP in a sibling and consanguinity of the parents. Low birthweight (less than 2000g), gestational age less than 32 weeks, twin pregnancy and respiratory distress were significantly more frequent among CP cases than controls. The results suggest that antenatal factors, including inherited ones, play a major role in the pathogenesis of CP in Saudi Arabia, which is contrary to previous reports from this region. Their contribution to the pathogenesis of CP in developing countries may be greater than previously assumed.

Pattern and ethnic variations in stroke in Saudi Arabia

We report our observations in 427 stroke patients (305 Saudis, 122 non-Saudis with an age range of 14 months to 85 years) seen in a tertiary hospital in the eastern province of Saudi Arabia over an 8-year period. Of these patients, 115 (27%) were between 18 and 45 years old, and constituted the "young stroke patients" for this study. The hospital frequency for the young was 5/10,000 inpatients. In general, there was a male preponderance, with a male:female ratio of 2.2:1 and 7:1 for Saudis and non-Saudis, respectively. Ischemic stroke (55%) was more frequent than hemorrhagic stroke (25%), and the stroke was unspecified in 20%. The main etiologic factors were hypertension, diabetes mellitus and cardiac disorders. In the young population, the frequencies of hemorrhagic and ischemic strokes were similar. In this group, the main causes of intracerebral hemorrhage were aneurysms and arteriovenous malformations, while arteriosclerosis and embolism of cardiac origin were responsible for the ischemic strokes. In Saudis, the stroke types were 59% ischemic, and 17% hemorrhagic, as against 45 and 48% in non-Saudis, respectively. Most ischemic strokes were found in Saudis (78%). Intracerebral hemorrhage accounted for 63% of all hemorrhagic strokes, and was more frequent in Saudis but subarachnoid hemorrhage was three times more common in non-Saudis. In the young stroke patients, interethnic comparison showed that individuals from the Far East were nine times more likely to have hemorrhagic than ischemic stroke compared to the others (odd's ratio = 8.7), and the etiology of ischemic stroke remained undetermined in 67% of those from the Indian subcontinent.(ABSTRACT TRUNCATED AT 250 WORDS)

Excessive sweating: an uncommon sign of basilar artery occlusion

Excessive sweating of the face and, to a lesser degree, of the thorax and limbs, occurred after basilar artery occlusion in a 15 year old Saudi boy. Magnetic resonance imaging (MRI) showed a limited bilateral paramedian infarction of the rostral ventral pons. Basilar artery occlusion in children and adolescents is a rarity. Excessive sweating following such a stroke is rare in any age group. Clinico-anatomical correlations are discussed.

Stroke in a tertiary hospital in Saudi Arabia: a study of 372 cases

Epidemiological studies have shown a consistent downward trend in the incidence and mortality of stroke in industrialized communities. There are however no reports on the pattern of stroke in Saudi nationals and expatriates in Saudi Arabia. The types and etiologies in 372 subjects (262 Saudis, 110 non-Saudis) are described. Males outnumbered females in the ratios of 2.2:1 and 8.2:1 for Saudis and non-Saudis, respectively. The frequency of stroke increased steadily with age until the 7th decade in Saudis but dropped sharply after the 6th in expatriates. The frequency of stroke types in Saudis was ischemic (61%), hemorrhagic (17%) and unspecified (22%) as against 46, 47, and 7% respectively in non-Saudis. Intracerebral hemorrhage was more frequent than subarachnoid hemorrhage (SAH) and was encountered more often in Saudis than in non-Saudis; SAH was 3 times more common in expatriates than in Saudis. The major predisposing factors for stroke were hypertension, diabetes mellitus, and cardiac disorders. Abnormal hemoglobinopathies, especially sickle cell anemia, were rare. The differences observed in the age and sex distribution and in the stroke pattern between Saudi nationals and expatriates most likely reflect the demographic structure existing in Saudi Arabia.

Epilepsy and other convulsive disorders in Saudi Arabia: a prospective study of 1,000 consecutive cases

The pattern of epilepsy and other convulsive disorders in 1,000 consecutive Saudi nationals is described. These disorders were common with a hospital frequency rate of 8 per 1,000. Men were more frequently affected than women and 60% of the patients were under 10 years old at the onset of their illness. The epilepsies were the commonest type (74%). Febrile convulsions (20%) presented mainly between the ages of one and five years. Isolated seizures (3%) and acute symptomatic convulsions (3%) were uncommon. In the epileptic group, generalised seizures (71%) were more frequent than partial (29%) and complex partial seizures occurred mainly in those above 21 years old. Absences (4%), infantile spasms (3%) and atonic seizures (3%) were uncommon. No specific etiology of the epilepsy was determined in the majority of the cases (63%). The identified major etiologic factors of the epilepsies were perinatal encephalopathy (21%), cerebral trauma (11%), sequelae of meningitis or encephalitis (2%), brain tumors (0.5%), and vascular lesions such as stroke and arteriovenous malformation. Perinatal encephalopathy accounted for 40% of the epilepsies in children less than 5 years old, and trauma for 20% of those above 20 years old. A family history of epilepsy in close relations was obtained in 23% of the cases, and the consanguinity rate among the parents was 53%. The high incidence of associated perinatal encephalopathy found in this study suggests that perinatal factors play a major role in the pathogenesis of epilepsy in Saudi Arabia. The high frequency of cerebral trauma was also striking. Although consanguinity of the parents appeared not to be a major factor in the genetics of convulsive disorders in this environment, it might have potentiated the tendency of familial aggregation of convulsive disorders in this community. Consanguinity may be an important factor in the production of some of these disorders but its precise role has not been determined.

Headache syndromes in the eastern province of Saudi Arabia

The pattern of headache syndromes in 222 subjects (142 Saudi nationals, 80 non-Saudis) seen at Al-Khobar, Saudi Arabia is presented. Headaches were common, and accounted for 13% of all neurological outpatients. They affected mainly young adults, with a peak frequency in the third decade for Saudis and the fourth for non-Saudis. They were rare in those under 10 and above 50 years old. Among Saudis, females outnumbered non-Saudi males were more frequent than females in all age groups except the second decade. The main types were tension headache (66%) and migraine (22%). Acute/chronic sinusitis was an uncommon cause of headache. Tension headache affected mainly individuals between 21 and 40 years of age (69%). It showed a female preponderance in Saudis aged 11-20 and above 40 years, unlike the male predilection in non-Saudis. Migraine showed a definite female predilection only in Saudis in the fourth decade (female to male ratio of 4:1). A positive family history for headache was present in 10% of the cases. The major precipitating factor for headaches was stress related to family or working conditions. Other triggers included hunger and prolonged exposure to excessive heat or sunlight. The pattern of headaches in Saudi nationals may be related to the prevalent sociocultural factors, and the differences observed between them and non-Saudis probably reflect the demographic status of non-Saudis in the Kingdom as a consequence of governmental recruitment policy.

Congenital brachial palsy in the eastern province of Saudi Arabia

The clinical features of 57 patients (31 males, 26 females) with congenital brachial palsy seen at the King Fahd Hospital of the University over a 5-year period are described. Delivery was difficult in 32 (56%), 20 (35%) were large babies (birth weight greater than 3,600 g), and 20 deliveries required either forceps or vacuum extraction. The presentation at delivery was vertex in 45, breech in five, and shoulder in four. Associated injuries or features, encountered in 14 cases, were fractures of the clavicle and humerus (six cases each), and skull fracture and Horner's syndrome in one patient each. The right and left sides were involved in 31 and 24 cases, respectively, and both sides in only two cases. All the muscle groups of the affected limb were most commonly involved (40%), and hand muscles alone were affected in only one patient. Although 60% of the cases presented late to the hospital, functional recovery was observed in 63%. The major predisposing factors identified in this study were technically difficult deliveries, large infants, and breech or shoulder presentation with assisted delivery. It is suggested that early identification of these factors and improvement in obstetric care of both the mothers and babies during delivery would reduce the incidence and severity of this disability.

Effect of diltiazem on 2,4-D-induced myotonia in rats

Myotonia is characterized by prolonged contraction (delay in onset of relaxation) of skeletal muscle fibers with characteristic electromyographic findings. Calcium channel blocking drugs may be expected to reduce myotonia, should they promote the onset of relaxation in a contracted skeletal muscle. This study was aimed at evaluating the effect of diltiazem, a calcium channel blocking agent, on myotonia induced by 2,4-dichlorophenoxyacetic acid (2,4-D). In rat diaphragm, exposed to 2.5 mM 2,4-D in a tissue bath, myotonia was quantified by documenting the contraction time in response to direct stimulation with supramaximal electric stimuli. At the peak of myotonia, different concentrations of diltiazem were added to the tissue bath and the effect on evoked contraction studied over a period of 6 minutes. A concentration of 5 x 10(-5) M was found to be the most effective, causing a decrease in contraction time of more than 90% in 3 minutes in 100% of specimens (n = 7). The above findings raise the possibility of using diltiazem as an antimyotonic agent.