Dementia in Kerala, South India: prevalence and influence of age, education and gender.

BACKGROUND: Data on the prevalence of dementia in India with a large and aging population is scant. We studied prevalence of AD and dementia in Kerala, South India, and effects of age, education and gender on it. METHODS: 2-phase survey on 2466 individuals aged > or = 55 years living in community. Men constituted 41%, < 75 years age in 76.9% and education > or = 4 years in 69.6%. Screening (Phase I) using the instrumental activity of daily living scale for the elderly (IADL-E) and the Addenbrooke's cognition examination (ACE). Diagnostic-assessment (Phase II) was in 532 screen-positives and 247 (10%) screen-negatives. RESULTS: 93 (3.77%) > or = 55 years and 81 (4.86%) > or = 65 years of age had dementia. Age adjusted (against US-population in 2000) dementia (and AD) rates were 4.86% (1.91%) in age > or = 55 years and 6.44% (3.56%) in > or = 65 years. Odds for dementia (and AD) were high with increasing-age 5.89 (15.33) in 75-84, 13.23 (25.92) > or = 85 years, and in women 1.62 (2.95); and low 0.27 (0.16) if education was > or = 9 years. Age and low education increased dementia. Age and female gender increased AD. CONCLUSION: Prevalence of dementia and AD is higher than any reported from the subcontinent suggesting that dementia in Kerala in South India is not uncommon. Increasing age increased dementia and AD. Low-education is associated with dementia and female-gender with AD.

Ictal nystagmus in a newborn baby after birth asphyxia.

Ictal nystagmus (IN) is an uncommon phenomenon characterized by rhythmic saccadic eye movements occurring during epileptic seizures. We report a newborn baby with severe birth asphyxia, undergoing long-term video EEG monitoring with electro-oculogram (EOG), who showed irregular IN when eye movements crossed the midline from left to right and vice versa, resulting in large amplitude of the nystagmoid movements. The nystagmus was followed 15 to 29 seconds later by ictal discharges in the occipital regions. MRI of the brain showed features suggestive of periventricular leukomalacia. This interesting combination of findings suggests a complex mechanism for IN of cortical or subcortical ictal rhythms, which results in (a) the generation of subcortical electrical discharges in the pons and midbrain, causing nystagmoid eye movements, and (b) subsequent occipital spiking. We conclude that this clinical manifestation supports the existence of functioning cortical-subcortical connections between the brainstem ocular motor centers and the occipital cortex at birth.

Instrumental activities of daily living scale for dementia screening in elderly people.

OBJECTIVE: To develop and validate an Instrumental Activities of Daily Living Scale for elderly people (IADL-E) to use in conjunction with cognitive screening tests for dementia in an educationally and socioculturally heterogeneous population. METHOD: Eleven IADL items were selected and weighted for major factors causing heterogeneity in the population--gender, education, social (rural/urban) setting and age. Each item was rated for its applicability (yes/no), degree of disability (scored from 0 to 2) and causative impairment (cognitive and/or physical). From this a composite index of cognitive (CDI) or physical (PDI) disability was derived. Validation was performed retrospectively on 240 subjects: 135 without and 105 with dementia by DSM-IV. RESULTS: The IADL-E had a high internal consistency (alpha = 0.95). The area under the receiver operating characteristic (ROC) curve was 0.97 (CI = 0.94-0.99). A cutoff score of 16 on CDI provided a sensitivity of 0.91, specificity 0.99 and positive predictive value 0.76 (at 5% base rate). IADL-E correlated highly with clinical (DSM-IV, kappa = 0.89), functional (CDR, 0.82) and cognitive (Mini-mental Status Examination, MMSE, 0.74) diagnoses. It showed good responsiveness, with the change on CDI over a median of 23 months correlating significantly with that on MMSE (coefficient = -0.382, CI = -0.667 to -0.098; p=0.009). Individual items had good interrater and test-retest reliability. CONCLUSIONS: The IADL-E is a reliable, sensitive and responsive scale of functional abilities useful in dementia screening in a socioculturally heterogeneous population.

Adaptation of the ACE for a Malayalam speaking population in southern India.

OBJECTIVE: To adapt the Addenbrooke's Cognitive Examination (ACE) as a dementia-screening tool in a community in south India. To establish that items in the adapted version are equivalent to that in the original. METHODS: The ACE was adapted into the local language, Malayalam (m-ACE), following cultural/linguistic modifications. To establish equivalence, qualitative comparisons were made (on the distribution of scores, percentage scoring at ceiling, and relative difficulty across items) between a UK sample receiving the ACE (n = 50; mean age = 67.9 +/- 7.4; education >/= 9, mean = 10.9 +/- 2.5) and a community-based educationally-stratified Indian sample receiving the m-ACE: 'India >/= 9' (n = 50; mean age = 67.8 +/- 5.2; education >/= 9, mean = 13.9 +/- 2.7) and 'India /= 9 groups. Language, Naming, Attention and Orientation are relatively easy (>/= 80% at ceiling) and Recall and Verbal fluency are relatively difficult (

Zeta waves, an unusual EEG finding in structural brain lesions: report of two patients.

We report two patients with acute cerebral conditions and zeta waves on their EEGs. The first patient, a 48-year-old lady, had acute disseminated encephalomyelitis (ADEM)following afebrile illness. Neurological examination showed expressive dysphasia and a mild right hemiparesis. The magnetic resonance imaging (MRI) scan of the brain showed multiple, bilateral, subcortical white matter hyperintensities, predominantly in the centrum semiovale region of the left hemisphere, and also in the corpus callosum. An EEG done 21 days after the onset of the neurological deficit showed intermittent, sharply contoured, predominantly biphasic delta waves (zeta waves) over the left frontotemporal region. The second patient was a 2-year-old child, who had a head-injury resulting in bilateral, frontoparietal fractures of the skull; acute epidural hematoma on the left frontoparietal region; and a cerebral contusion on the right frontotemporal region. An EEG done one day after the evacuation of the hematoma showed zeta waves over the right frontal region. To the best of our knowledge, the association of zeta waves and ADEM has not been previously reported. The EEG findings in our patients again supports the hypothesis that these waves are seen predominantly in patients with structural brain lesions. Other conditions causing zeta waves in the EEG are briefly reviewed.

The significance of corpora amylacea in mesial temporal lobe epilepsy.

Temporal lobe epilepsy (TLE) associated with mesial temporal sclerosis (MTS), mesial TLE (MTLE), is the commonest medically refractory adult epilepsy syndrome. Corpora amylacea (CoA) have been shown to be a marker of MTS. We compared 9 patients with MTS who had dense deposition of CoA in their hippocampi with 25 patients with MTS who did not have CoA. The patients with CoA were significantly older and they showed a trend towards having a significantly longer duration of epilepsy. The postoperative seizure outcome at 2 years was not different in the 2 groups. Our results could indicate the progressive nature of the pathology of MTS, probably indicating excitotoxic damage due to recurrent seizures, but they need to be verified by clinicopathological correlation among a larger number of patients with MTLE.

Emotional facial paresis in temporal lobe epilepsy: its prevalence and lateralizing value.

The selection of patients with medically refractory temporal lobe epilepsy (TLE) for surgery depends on the concordance of data from clinical, imaging and electroencephalographic evaluation. Though clinical examination is often normal, emotional facial paresis has been described in patients with TLE. Utilizing a well-characterized group of mesial TLE (MTLE) patients, who have achieved excellent seizure outcome following anterior temporal lobectomy with amygdalohippocampectomy (ATL), we investigated the prevalence, predictive value and associations of emotional facial paresis. When compared to 8 out of 50 control subjects (16%), 36 out of 50 MTLE patients (72%) exhibited unilateral emotional facial paresis; the difference was highly significant (P<0.0001). The presence of contralateral emotional facial paresis correctly predicted the side of ATL in 86.1% patients. The occurrence of emotional facial paresis was significantly associated with longer duration of epilepsy prior to ATL and left ATL. Our observations confirm that emotional facial parersis contralateral to the side of mesial temporal sclerosis (MTS) is a valuable localizing sign in correctly predicting the epileptogenic temporal lobe. We hypothesize that the presence of an intact right hemisphere and pathological changes more extensive than MTS may be required for emotional facial paresis to readily manifest.