Event-related evoked potentials in chronic respiratory encephalopathy.

BACKGROUND: Cognitive event-related potential (P(300)) is an index of cognitive processing time. It was found to be prolonged in dementia, renal, and hepatic encephalopathies, but was not extensively assessed in respiratory failure. OBJECTIVE: To evaluate P(300) changes in patients with respiratory failure, and especially those with mild or subclinical hypoxic-hypercapnic encephalopathy. METHODS: Auditory event-related evoked potential P(300) latency was measured using an oddball paradigm in patients with respiratory failure due to any cause (partial pressure of oxygen in arterial blood (PO(2)) should be 75 mm/Hg or less). Apart from blood gases measurement, patients underwent the Mini-Mental State Examination (MMSE). Patient performances were compared with that of matched normal control. Patients were admitted into the study from outpatient clinics and wards at King Khalid University Hospital and Sahara Hospital. RESULTS: Thirty-four patients (12 women, 22 men) were admitted to the study. Ages ranged from 19-67 years with a mean of 46.1 years. Respiratory failure was severe or very severe in 11 patients (33%), and mild or moderate in the rest (66%). Mean value for PO(2) and partial pressure of carbon dioxide in arterial blood (PCO(2)) were 63.7 and 45.2 mm/Hg, respectively. pH mean was 7.4 and O(2) saturation was 90.7%. P(300) latency ranged from 218 to 393 milliseconds, with a mean of 338.4 milliseconds. In comparison with control (309.9 milliseconds), there was a significant difference (P = 0.007). P(300) amplitude differences were not significant. No significant difference in MMSE was noted between mild and severe respiratory failure. Results of detailed neuropsychological assessment were clearly abnormal but were limited by the small number of tested patients. P(300) latency changes correlated significantly with age as well as severity of respiratory failure. P(300) was also significantly delayed whether hypoxia occurred with or without hypercapnia. CONCLUSION: Results show a significant delay of P(300) latency in patients with severe and mild respiratory failure. This was associated with subclinical encephalopathy in most patients, evidenced by a near-normal MMSE score. Apart from confirming the importance of P(300) latency measurement as a marker of respiratory encephalopathy, this study asserts the causal relationship between hypoxemia and cognitive derangement. Furthermore, it promotes the early use of oxygen therapy in a selected group of patients with mild or moderate respiratory failure, who have responsibilities which involve taking rapid critical decisions.

Behaviour and time-course of sleep disordered breathing in patients with acute coronary syndromes.

To our knowledge, no study has examined the persistence of sleep disordered breathing in acute coronary syndrome (ACS) patients. We examined the time course of SDB in ACS patients by assessing them within days of the acute event and again after 6 months. Consecutive patients with ACS were asked to voluntarily participate in the study. Patients underwent an overnight polysomnography (PSG) approximately 3 days after the acute event. Patients with an apnea hypopnea index (AHI) > 10/h then underwent another PSG after they were stable (approximately 6 months). Fifty patients were studied. First PSG showed an AHI was 23.1 +/- 3.6/h. A second PSG was performed 6.1 +/- 0.3 months later on 21 patients and showed an AHI > 10/h in the first assessment. The AHI and the obstructive apnea index did not change over the 6 months. However, the central apnea index all was lower at the second assessment.

Thrombosis complicating high dose intravenous immunoglobulin: report of three cases and review of the literature.

High dose intravenous immunoglobulin (IVG) is increasingly used in a broad range of immune mediated diseases. Thrombosis was exceptionally reported as a complication of this therapy. We describe three cases of thrombotic complications during or soon after IVIG treatment: myocardial infarction in a man and cerebral infarctions in an elderly man, associated with peripheral ischemia in a woman. In addition we review the published cases in the literature and discuss the possible etiologic factors.

Paradoxic response to diazepam in complex partial status epilepticus.

BACKGROUND: Antiepileptics including benzodiazepines have long been recognized to provoke seizures and precipitate status epilepticus occasionally. This has a special clinical importance in the case of diazepam because of its use as first choice medication in its management. This report is intended to highlight the clinical importance of such a situation. METHODS: The clinical course of a 28-year old man with complex partial status, which lasted for two months, is described in detail. RESULTS: Paradoxic response to diazepam was documented under EEG monitoring. A similar response was also noted for midazolam, and had probably contributed in exacerbating and prolonging the duration of status. CONCLUSION: Paradoxic response to diazepam and midazolam is rare, but may be under-recognized. It should be considered in the setting of refractory status epilepticus.

Localization of the gene for a novel autosomal recessive neurodegenerative Huntington-like disorder to 4p15.3.

A consanguineous family affected by an autosomal recessive, progressive neurodegenerative Huntington-like disorder, was tested to rule out juvenile-onset Huntington disease (JHD). The disease manifests at approximately 3-4 years and is characterized by both pyramidal and extrapyramidal abnormalities, including chorea, dystonia, ataxia, gait instability, spasticity, seizures, mutism, and intellectual impairment. Brain magnetic resonance imaging (MRI) findings include progressive frontal cortical atrophy and bilateral caudate atrophy. Huntington CAG trinucleotide-repeat analyses ruled out JHD, since all affected individuals had repeat numbers within the normal range. The presence of only four recombinant events (straight theta=.2) between the disease and the Huntington locus in 20 informative meioses suggested that the disease localized to chromosome 4. Linkage was initially achieved with marker D4S2366 at 4p15.3 (LOD 3.03). High-density mapping at the linked locus resulted in homozygosity for markers D4S431 and D4S394, which span a 3-cM region. A maximum LOD score of 4.71 in the homozygous interval was obtained. Heterozygosity at the distal D4S2366 and proximal D4S2983 markers defines the maximum localization interval (7 cM). Multiple brain-related expressed sequence tags (ESTs) with no known disease association exist in the linkage interval. Among the three known genes residing in the linked interval (ACOX3, DRD5, QDPR), the most likely candidate, DRD5, encoding the dopamine receptor D5, was excluded, since all five affected family members were heterozygous for an intragenic dinucleotide repeat. The inheritance pattern and unique localization to 4p15.3 are consistent with the identification of a novel, autosomal recessive, neurodegenerative Huntington-like disorder.

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.

A novel autosomal recessive "Huntington's disease-like" neurodegenerative disorder in a Saudi family.

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Terminal Latency Index: A distinctive diagnostic criterion for carpal tunnel syndrome.

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The pattern of brachial plexus lesions.

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Spectrum of inherited myotonias and periodic paralyses.

Full text is available as a scanned copy of the original print version.

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

Dementia in Saudi Arabia: experience from a university hospital.

OBJECTIVES: To describe the pattern of presentation, the types of dementia and the associated conditions in Saudi patients. MATERIALS AND METHODS: Hospital-based study using DSM-IV and ICD 10 criteria for consensus diagnosis of cases from clinical information and results of investigations. Dementia subtypes were made according to NINCDS-ADRDA, NINDS-AIREN and ICD 10 criteria while CDR was used for severity grading. RESULTS: A total of 77 demented patients (49 males, 28 females) were studied. The hospital frequency was 19.3/100,000 patients. The mean age at presentation was 74.6 years and age at onset was below 65 years in 17 patients. The types of dementia were: Alzheimer's disease (51.9%), vascular dementia (18.2%), mixed cases (15.6%), dementia with Parkinson's disease (7.8%) and treatable dementia (5.2%). Only 3 patients were in the severe clinical stage and infections were important causes of deterioration. CONCLUSION: The hospital frequency appears to be low probably because of the relatively young population. The pattern of dementia with preponderance of AD is similar to that in western countries and intervention directed at the risk factors for stroke could reduce the burden of vascular dementia.

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.

Pattern of presentation of multiple sclerosis in Saudi Arabia: analysis based on clinical and paraclinical features.

We studied 89 MS patients comprising 38 males and 51 females seen over a 10-year period. The hospital frequency was 25/100,000 patients. The diagnosis was mainly clinical and was supported by neuroimaging, cerebrospinal fluid analysis and neurophysiological tests. Sixty-five patients (73%) were Saudis and the peak age of onset was in the third decade. Fifty-two patients (58.4%) had clinically definite MS, 17 (19.1%) had laboratory-supported definite MS, 15 (16.9%) were clinically probable MS cases and the remaining 5 (5.6%) had laboratory-supported probable MS. The mean age at onset of Saudi patients (25.9 years) was lower than that of the non-Saudis (29.4 years; p < 0.001). Involvement of the pyramidal system was the commonest mode of presentation. The clinical course was relapsing-remitting in 60.7%, progressive-relapsing in 20.2% and primary progressive in 19.1%. The number of systems involved was significantly associated with the duration of disease (p < 0.001). The demographic features and the variability of clinical presentation of Saudi MS patients is similar to the results from neighbouring countries. Combination of clinical features and paraclinical tests is essential for accurate determination of extent of dissemination and for unmasking clinically silent lesions.

Epilepsy classification and factors associated with control in Saudi adult patients.

There is insufficient information on the epilepsies in Saudi Arabia. The objectives were to classify the patients according to seizure types and epilepsies as well as to determine the factors associated with control. In a hospital-based study, clinical information, electroencephalographic and neuroimaging findings were utilized to classify the cases into seizure types and epilepsies according to ILAE criteria and to determine the factors statistically associated with control. In the study there were 826 patients (454 males and 372 females; mean age = 28.7 years; >80% below 30 years at onset). The seizure types were: generalized tonic-clonic (43.8%), partial seizure secondarily generalized (41.9%), myoclonic (8.4%), simple partial (1.3%), complex partial (1.3%) and absence (0.4%). About 15% of the classifiable epilepsies were symptomatic. Most symptomatic epilepsies occurred in people over the age of 50 years. One-year remission rate was 80% and the factors associated with control were: compliance, monotherapy, therapeutic drug level and seizure type. The results showed that epilepsy predominantly affected young adults and confirmed the association of partial epilepsy with clinical and CT abnormalities. The 1-year remission rate was comparable with reports from other studies as well as the factors associated with control in our patients.

Centro-temporal benign epilepsy in Saudi children.

A review of 36 interictal EEGs compatible with the diagnosis of benign childhood epilepsy with centro-temporal spikes (BECTS) was made in this study. These children constituted 31% of the children with focal epileptic EEG activity observed in the same period. The dipolic spikes occurred either as a single focus (78%) or as two independent foci with a greater preponderance to the right (22%). The onset of seizures before the age of 5 years (Group I) is 53% and between 6 and 10 years (Group II) is 47%. Clinical evaluation showed that 60% of the patients in Group I and 75% in Group II had lateralized seizures, although all of them were initially diagnosed as nocturnal generalized tonic-clonic seizures. A follow-up study showed 31% complete recovery, 47% seizure-free under medications, 8% occasional seizures, 8% frequent seizures, and the rest 6% had a single seizure without medication. It is therefore concluded that the syndrome is common in Saudi Arabia and is usually unrecognized by the general physicians. The follow-up of our patients so far confirms the excellent prognosis.