Effect of hyperventilation on electroencephalographic activity.

OBJECTIVE: To observe the effect of voluntary hyperventilation on electroencephalographic activity during routine EEG recording on patients referred to a tertiary care hospital. METHODS: This was an observational study conducted at Neurophysiology Lab, Department of Neurology at Liaquat National Hospital, Karachi from May 2007 to September 2007. Data of 326 patients was collected prospectively and analyzed by SPSS version 10.0. At least 3 minutes voluntary hyperventilation was performed by the subjects. All those patients who were able to perform voluntary hyperventilation adequately were included in the study. RESULTS: Of 326 recordings, 256 (78.8%) were normal and 69 (21.2%) were abnormal. Focal epileptiform discharges were identified in 8.6% and generalized in 8.3% of subjects. Physiological slowing was found in 31 records. Out of 55 epileptics, 3 had discharges only during HV and 9 had increase in epileptiform discharges. CONCLUSION: Hyperventilation has significant effect on background rhythm during EEG recording. It is a useful activation method utilized to increase the yield of EEG.

Frequency of non convulsive status epilepticus in patients with impaired level of consciousness.

OBJECTIVE: To determine the frequency of Non Convulsive Status Epilepticus in patients admitted with impaired consciousness. METHODS: All EEG's in patients with impaired level of consciousness over four years from 2002- 2006 were reviewed. All EEG's showing continuous epileptiform discharges were included. Findings of all these EEG's were divided into five groups; generalized spikes and wave, generalized sharp and wave, focal spike and wave, focal sharp and wave and periodic lateralized epileptiform discharges. RESULTS: There were 785 EEG's recorded in patients with impaired level of consciousness. Only 12 (1.5%) patients were identified with NCSE on EEG. The commonest EEG findings in our patients with NCSE were: Continuous focal spike and wave seen in 4(33%), Continuous generalized spike and wave 3 (25%), Continuous generalized sharp and wave 3 (25%), Continuous focal sharp and wave 1 (8.3) and Continuous periodic lateralized epileptiform discharges (PLEDs) in 1 (8.3%) patient. CONCLUSION: NCSE is an important treatable entity which can be easily recognized by doing an EEG.

Clinical and radiological features of intracerebral haemorrhage in hypertensive patients.

OBJECTIVE: To describe clinical and radiological features of intracerebral haemorrhage in hypertensive patients. METHODS: This is a descriptive case series, carried out prospectively over a period of 6 months at, department of neurology, Liaquat National Hospital, Karachi. Hypertensive patients > 25 years of age, presenting with features of stroke and verified by either CT scan or MRI brain as having intracerebral haemorrhage, were included. Clinical and radiological features were identified. Atotal of 100 patients were included in the study. Data was analyzed by SPSS version 10.0. RESULTS: There were 62% males and 38% females. Mean age was 56 +/- 12 years. Diabetes mellitus was present in 30% and ischaemic heart disease in 26% patients. Of all, 28% were smokers. Hemiparesis or hemiplegia (78%) was the commonest presenting feature followed by speech dysfunction (60%). Headache and vomiting were present in 20% and seizures in 9% cases. Basal ganglia (55%) was the commonest site of bleed followed by thalamus (26%), cerebral hemispheres (11%), brain stem (8%) and cerebellum (7%). CONCLUSION: Hypertensive intracerebral haemorrhage was more common in males as compared to females in our study. Hemiparesis and speech disturbances were frequent presenting features. The commonest site of bleeding was basal ganglia followed by thalamus and cerebral hemispheres.

Cerebral venous thrombosis: a descriptive multicenter study of patients in Pakistan and Middle East.

BACKGROUND AND PURPOSE: The natural history, causative factors, and outcomes of patients with cerebral venous thrombosis from Asia and Middle East have not been well described. This descriptive multicenter study describes the results for cerebral venous thrombosis patients in South Asia and the Middle East. METHODS: The retrospective and prospective data of patients with radiologically confirmed cerebral venous thrombosis were collected from 4 centers located in Pakistan and United Arab Emirates. The demographic, clinical, radiological, and outcome data were recorded and analyzed. Primary outcome was death or dependency (modified Rankin score >2) at the time of hospital discharge. RESULTS: This study included 109 patients with cerebral venous thrombosis; the presenting features most commonly being observed were headache (81%), focal motor deficits (45%), seizures (39%), and mental status changes (37%). Important predisposing factors included systemic and central nervous system infection (18%), postpartum state (17%), hyperhomocystinemia (9%), genetic thrombophilia (5%), and oral contraceptive pill use (3%). Ninety-six (67%) patients received therapeutic anticoagulation. Seven patients died and 43 had poor outcome at discharge. Focal motor deficits (OR, 2.93; 95% CI, 1.2-7.5; P=0.018) and hemorrhagic infarctions (OR, 2.81; 95% CI, 1.04-7.85; P=0.041) were independent predictors of unfavorable outcome at discharge. Hemorrhagic infarction was the most significant factor of long-term unfavorable outcome (OR, 5.87; 95% CI, 1.49-23.02; P=0.011). CONCLUSIONS: Infections and postpartum state were the most common predisposing factors for cerebral venous thrombosis in this cohort. Most patients (67%) were treated with anticoagulation therapy. Almost 50% of patients were dead or disabled at discharge.

Factors delaying hospital arrival of patients with acute stroke.

INTRODUCTION: To determine the proportion of patients with acute stroke presenting late to hospital and to identify the factors that delay hospital arrival of patients with acute stroke. METHODS: A cross sectional study was carried out between Sept 2006 to Feb 2007 in the department of Neurology, Liaquat National Hospital Karachi. All patients of both genders, ago >18 years with symptoms of stroke and neuro- imaging (CT scan/MRI brain) findings consistent with stroke were included. RESULTS: Atotal of 165 patients attending the Emergency department were included. There were 86 (52%) males and 79 (47.9%) females. The mean age was 60.04+/-13.98 years, (males 58.2 years and females 61.9 years). The median delay from onset of symptoms to hospital arrival was six hours. Only 28.5% of the patients came within three hours while 71.5% after three hours. Attendants of 47 patients had a low throat perception, 53 (32%) of the patients did not know a single symptom of stroke and 63% (104) patients first contacted their General Practitioner who referred them to hospital. Similarly 60.6% of patients wore first taken to a local hospital not equipped to handle major emergencies. CONCLUSION: Time elapsed from onset of symptoms to hospital arrival is influenced by lack of knowledge of stroke symptoms, contact with a local doctor, low threat perception and non availability of ambulance services.

Pattern of stroke in type 2 diabetic subjects versus non diabetic subjects.

BACKGROUND: Diabetes mellitus is a well-recognized risk factor for ischaemic stroke. Stroke in diabetic patients is different from stroke in non-diabetics from several perspectives. There is no local study on this topic. This is the first study from Pakistan, in which pattern of stroke in diabetics have been described and compared with non-diabetics. The object of this study was to compare pattern of stroke in diabetic subjects with non-diabetics. METHODS: This is a prospective comparative cross sectional study, carried out at Liaquat national hospital, Karachi, neurology department from October to March 2006. Fifty patients were enrolled in diabetic group and 50 in non-diabetic. Clinical features, risk factors and stroke patterns were identified. RESULTS: Mean age was 59.5 (+/- 11.82) in diabetics and 60.4 (+/- 14.8) in non diabetics. There was slight preponderance of male patients in non diabetic group. Out of 50 diabetic patients, 44 (88.0%) had ischaemic stroke and 6 (12.0%) had intracerebral haemorrhage. In non-diabetics, 29 (58.0%) had ischaemic stroke while 21 (42.0%) had intracerebral haemorrhage. On further analysis of ischaemic stroke, cortical infarcts (CI) was found in 22, sub cortical infarcts (SCI) in 14, brainstem in 5 and cerebellar in 2 diabetic patients. CI was also the commonest subtype of ischaemic stroke in nondiabetics. CONCLUSION: Patterns of stroke in diabetics are different from non-diabetics. Ischaemic stroke is more prevalent than hemorrhagic strokein diabetics. Sub cortical infarcts are more common in diabetics than non diabetics (p = 0.04).