Kurupath Radhakrishnan

Predictors of outcome of anterior temporal lobectomy for intractable epilepsy: A multivariate study

Objective: To identify presurgical and postsurgical factors that are independently predictive of the outcome of anterior temporal lobectomy (ATL) for intractable epilepsy. Background: There have been reports of prognostic studied 175 consecutive ATL patients who had at least 2 years of postsurgical follow-up. Significant factors on univariate analyses were subjected to stepwise logistic regression analysis. Results: On univariate analyses, two presurgical conditions were significantly associated with excellent seizure control at last follow-up: (1) unilateral hippocampal formation atrophy as detected on MRI and (2) all scalp interictal epileptiform discharges concordant with the location of ictal onset(p < 0.05). Three postsurgical factors that occurred during the first year were associated with excellent seizure outcome: the absence of interictal epileptiform discharges at 3 months, complete seizure control, and having only nondisabling seizures for those who did not become seizure free. Logistic regression analysis revealed the following to be independently predictive of excellent seizure control: MRI-detected unilateral hippocampal formation atrophy, concordant interictal epileptiform discharges, complete seizure control during the first postsurgical year, and having only nondisabling seizures during the first postsurgical year for those who did not become seizure free. Conclusions: Presurgical identification of unilateral hippocampal formation atrophy, or of interictal epileptiform discharges that are all concordant with the location of ictal onset, predict excellent outcome of ATL. However, the probability of excellent outcome is highest (94%) when both factors are present.

Epidemiology of idiopathic intracranial hypertension: a prospective and case-control study.

An epidemiologic survey of idiopathic intracranial hypertension (IIH) in Benghazi, Libya, over a period from September 1982 through August 1989 ascertained 81 patients. The group was comprised of 76 females and 5 males. Ages ranged from 8 to 55 years; the mean +/- S.D. was 28.6 +/- 7.9 for women and 21.0 +/- 14.5 for men. The average crude annual incidence rates for IIH per 100,000 persons were 2.2 for the total and 4.3 for females for all ages (3.2 for the total and 5.9 for the females when adjusted to the 1980 United States population). In females aged 15-44 years, IIH occurred at a rate of 12.0 per 100,000 per year; for those defined as obese, the rate rose to 21.4. Moderate to severe visual loss occurred as a sequelae in 20% of our patients. The extent of visual loss did not correlate with age at diagnosis, duration of symptoms, degree of obesity, use of oral contraceptive pills, cerebrospinal fluid (CSF) opening pressure, steroid treatment, or recurrence. We found no correlation between CSF protein and opening pressure. We conducted a case-control study on 40 consecutive female incident IIH patients and 80 age-matched female control subjects. Obesity and recent weight gain occurred more frequently in patients. More patients were married and more had irregular menses. The incidence rate for IIH described in our study is three to four times higher than that reported from the United States.

Injuries due to seizures in persons with epilepsy A population-based study

Background: Previous studies of injuries due to epileptic seizures predominantly involved patients with intractable epilepsy. These studies may have overestimated the risk of injuries in persons with epilepsy. Methods: Patients consisted of 247 Rochester, MN, residents who were diagnosed with epilepsy between 1975 and 1984. Seizure-related injuries were defined as any injury, other than orolingual trauma, resulting from a seizure, sufficient for the patient to seek medical attention or for injury occurrence to be determined during the course of medical care. To identify risk factors for injury, characteristics of patients with seizure-related injury were compared with those without injury. Results: During a total of 2,714 patient-years of follow-up, 62 seizure-related injuries were identified in 39 patients (16%, one injury in every 44 person-years). Most injuries involved cranial soft tissue contusions or lacerations (79%). The majority of seizure-related injuries (82%) occurred during generalized convulsive seizures. Univariate analyses identified five potential risk factors for seizure-related injury: greater number of antiepileptic drugs used, less independent living situation, higher Rankin score, history of generalized convulsive seizures or drop attacks, and higher seizure frequency score. Seizure frequency, however, was the only significant risk factor identified by multivariate analysis (p < 0.001; relative risk, 1.33). Conclusions: This population-based study shows that seizure-related injuries are infrequent and generally of minor severity. In most epilepsy patients, excessive restriction of daily activities to avoid injury is unnecessary. Effective seizure control reliably reduces the risk of seizure-related injuries.

Mechanical trauma as a risk factor in classic amyotrophic lateral sclerosis: Lack of epidemiologic evidence

We have examined the relationship between mechanical injuries and the subsequent development of classic amyotrophic lateral sclerosis (ALS) through a critical review of the literature. Only prospective evaluation of a large cohort of trauma victims can provide an unbiased answer to this controversy. However, such an evaluation would be prohibitively expensive, and the results would not be available in our lifetime. The results of retrospective case-control studies are conflicting in part because of biases in the selection of patients and controls, poor definition of the nature and extent of the trauma and its chronological relationship to the onset of ALS, and a non-uniform approach to the collection of antecedent information. More rigorously designed studies show no association of ALS to antecedent trauma. The existing data thus do not suggest that mechanical trauma is a risk factor for ALS. Future case-control studies should conform to a standardized methodology. The critical analysis presented here of the research on the purported connection between mechanical injury and ALS may serve as a model for the evaluation of the role of trauma in other chronic diseases. Application of these methodological principles may bring increased scientific rigor to assessing the frequently litigated question of what constitutes a true trauma sequela.

Trauma and multiple sclerosis: A population‐based cohort study from Olmsted County, Minnesota

Utilizing the Olmsted County, Minnesota, population-based records-linkage resource at Mayo Clinic, we identified an incidence and a prevalence cohort with multiple sclerosis (MS), a head injury cohort, and a lumbar disk surgery cohort to evaluate the association between mechanical trauma and MS onset or exacerbation. The MS cohorts consisted of 225 incidence cases (1905 to 1991) and 164 prevalence cases (December 1, 1991) of definite MS in the population of Olmsted County. We assessed the effect of mechanical trauma in the form of spinal injury or extremity fracture with regard to precipitation of MS or exacerbation of an existing neurologic deficit. Fifty-four episodes of trauma, as defined, occurred among 39 MS prevalence cases; most occurred 10 years or more after the onset of disease and were associated with existing MS-related disability. We compared the final disability status of the groups with and without trauma. We found no correlation between the occurrence of peripheral fractures and the onset of MS, exacerbation of MS, or final disability due to MS in the prevalence cohort. In a cohort of 819 head injury cases from the Olmsted County population, none developed MS within 6 months of the trauma. In a lumbar disk surgery cohort of 942 local residents, there were five with MS, but onset of MS had preceded the spinal surgery in four of the five. Thus, we found no association of head injury and spinal disk surgery with onset of MS.

Conjugal amyotrophic lateral sclerosis Report of a young married couple

We report a 38-year-old nurse who developed amyotrophic lateral sclerosis (ALS) beginning in September 1990. In May 1991, her 38-year-old husband developed dysarthria, which progressed to typical ALS. This is the fourth report in the literature of conjugal ALS occurring outside of Guam. Although this event is most likely due to coincidence, exogenous agents should be considered in the etiology of ALS.