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Several studies have reported a seasonal variation in stroke incidence with a peak during winter. In a hospital-based study, we investigated the distribution pattern of stroke occurrence in general, as well as its subtypes throughout the year. We studied the monthly and seasonal distribution of acute stroke occurrence among 1299 first ever stroke patients admitted at our hospital and compared it with the assumed equal distribution of stroke over the year (null hypothesis) using chi2 techniques. The seasonal distribution of the different stroke subtypes was also examined. Overall stroke incidence shows a seasonal variation with a significant peak during wintertime. Stroke etiology, cardioembolic stroke, and intracerebral hemorrhage are also characterized from a similar seasonal fluctuation with a significant trough in summer and peak in winter. On the contrary, cases of stroke caused by atherosclerotic large vessel disease, small vessel disease, and stroke caused by unusual or undetermined types show no seasonal periodicity. Seasonal variation of stroke seems to depend primarily on the etiology of stroke. Further studies are necessary in order to clarify this issue and provide useful evidence for stroke prevention and therapy.

Objectives: For Greece, data on incidence of stroke, type of stroke, and prognosis of stroke is limited. Recently, results on incidence of stroke were published. Here 1 year mortality, functional outcome after a first ever stroke, and determinants of the prognosis are described., Methods: A population based registry was established in the Arcadia area, located in eastern central Peloponessos in southern Greece. Between 1 November 1993 and 31 October 1995, 555 patients with a first ever stroke were identified using information from death certificates, hospital records, public health centres and general practitioners. Extensive information on cardiovascular risk factors and stroke characteristics was obtained. After 1 year a modified Rankin score was determined in all surviving patients., Results: After 1 year of follow up, 204 (36.8%) patients died. The probability of survival 1 year after stroke was higher for cerebral infarction than for intracerebral haemorrhage; 67.8% (95% confidence interval (95% CI) 64-72) and 46.4% (35-57), respectively. Of the survivors, 68.9% had either no symptoms or symptoms that would not interfere with their capacity to look after themselves (Rankin score 0 to 2). Increasing age and low Glasgow coma scale score were the most powerful predictors of death within 1 year (p<0.01), whereas increasing age, atrial fibrillation, and low Glasgow coma scale score were the most important predictors of functional outcome 1 year after a stroke (p<0.01)., Conclusions: One year mortality from stroke in Greece is similar to that of other industrialised countries. The most important factors that affect the prognosis of a patient with a first ever stroke are increasing age, stroke severity, and atrial fibrillation.

The advent and wide application of new technology, especially noninvasive techniques, has enabled physicians to more completely investigate and clarify the etiopathogenic mechanisms of stroke. Such data have not been available until recently for Southeastern Europe. In addition, during the last decades, strategies for the modification of risk factors and primary prevention may have changed the prevalence of each subgroup of stroke as well. We investigated 1, 042 consecutive patients who had first strokes, during a period of 5 years (from June 1992 to May 1997) and classified them prospectively based on etiopathogenic mechanisms. Patients with transient ischemic attacks and subarachnoid hemorrhage were excluded. There were 613 male and 429 female patients, with a mean age of 70.2 +/- 11.9 years. Forty-six percent of the patients arrived within 3 h from stroke onset. The probable mechanisms were: large-artery atherosclerosis, 156 (15%); lacunes, 177 (17%); cardioembolic, 335 (32.1%); infarct of unknown cause, 182 (17.5%); miscellaneous causes, 35 (3.3%), and intracerebral hemorrhage (ICH), 157 (15.1%). In the cardioembolic group, nonvalvular atrial fibrillation (NVAF) was the probable cause in 225 patients, especially in patients older than 75 years (65%). The overall hospital mortality was 15.2% (from 0.6% for lacunar stroke to 34% for ICH). In our population, cardioembolism is the most frequent subtype of stroke. NVAF is the most likely source, especially in older patients., (Copyright 2000 S. Karger AG, Basel.)

Background and Purpose: For Greece, information on incidence of stroke and distribution of type of stroke has not been reported. We determined the incidence of first-ever stroke in men and women, the incidence of stroke by type, and the associated case fatality., Methods: A population-based registry was established in the Arcadia province, located in eastern central Peloponessos, in the southern part of Greece. Between November 1, 1993, and October 31, 1995, all subjects with a first-ever stroke were identified. For case ascertainment, information from death certificates, hospital records, public health centers, and general practitioners was used., Results: During a 24-month period, 555 subjects with a first-ever stroke were registered. The incidence rates (per 100 000) by age group (18 to 34, 35 to 44, 45 to 54, 55 to 64, 65 to 74, 75 to 84, >/=85 years) for men were 5, 31, 113, 240, 662, 1275, and 3218, respectively. For women, the rates were 11, 18, 48, 196, 478, 1166, and 2137, respectively. Age- and sex-standardized to the European population, the annual incidence rate for subjects aged 45 to 84 years was 319.4/100 000 (95% CI, 283 to 356). In men, cerebral infarction was diagnosed in 81% of cases, intracerebral hemorrhage in 16%, and subarachnoid hemorrhage in 2%. For women, these figures were 85%, 12%, and 3%, respectively. The 28-day case fatality rate was 26.6% (95% CI, 22.9% to 30.2%), with no differences between men and women. Case-fatality increased with age and was higher for intracerebral hemorrhage than for cerebral infarction., Conclusions: The incidence of stroke in our population-based study ranks low part compared with other European studies. The distribution of stroke types and case fatality rate appear to be similar to those of other industrialized countries.

Hereditary neuropathy with liability to pressure palsies (HNPP) is a peripheral nerve disorder characterized by autosomal dominant inheritance, recurrent pressure palsies, reduced motor and sensory conduction velocities and sausage-like swellings (tomacula) of myelin sheaths in nerve biopsy. Two young adult patients are reported as index cases of two families in which HNPP was diagnosed. The first patient presented with recurrent pressure palsies, whereas the second suffered from fasciculations and myokymias in his right hand, with difficulty in writing, and upper and lower limb paraesthesias of 3 years' duration. Electrodiagnostic studies revealed slowing of conduction primarily in common sites of compression in both patients. Sural nerve biopsy revealed the characteristic tomaculous swellings in both patients. DNA analysis showed that both patients have a deletion in chromosome 17p11.2 which is found in the majority of HNPP cases. In light of the common molecular defect, the different clinical symptomatology of the two patients is discussed.

Rats with kainic acid-induced lesions of the ventromedial thalamic (VMt) nucleus were compared with sham-operated controls on two behavioural tasks. The kainic acid injection resulted in loss of local neurons in the VMt nuclei with no appreciable damage to other thalamic nuclei or to other distant brain areas. VMt nuclei lesion animals learned to run in an L-maze for food reinforcement and to avoid electric foot-shock in the two way active avoidance shuttle-box procedure. Extinction of the food reinforced response was not altered by the lesion. One week retention of the acquired two-way active avoidance response was almost abolished on the animals with the lesion. Open field locomotion or escape latencies were not influenced by the lesion. It is concluded that VMt nuclei of rats are involved in the retention of aversively reinforced behaviours.