Stroke is known to human race since antiquity. The seventh century great Indian
physician, Charaka lucidly described the symptoms of stroke which he called
`Pakshaghat` meaning hit one half of body. The other synonyms are ardhang or
lakwa. According to Charaka, stroke affects either left or right side of body
leading to impaired mobility and function of that half of body (hemiparesis) and
difficulty in speaking which may be inability to talk at all (aphasia) or slurred
speech (dysarthria). He had also identified head as the seat of vital organ,
controlling the senses and nerve centers of the whole body. These meticulous
observations of stroke symptoms are relevant even today.
Stroke is one of the major causes of death disability and dependency among all the
neurological disorders. The World Health Organization (WHO) defines stroke as
rapidly developing clinical symptoms and / or signs of focal, at times global loss of
cerebral function, with symptoms lasting more than 24 hours or leading to death,
with no apparent cause other than of vascular origin.
The global prevalence of stroke is estimated to be 5 to 8 /1000. Globally stroke
incidence was also variable according to the ethnic differences in a common
geographical location and ranged from 93 to 223/1,00,000 population.
Epidemiology of stroke in India is difficult to study due to multiple factors. Nevertheless, many investigators have addressed this question in various regions of
India, which may be considered representative of the whole population. The crude
prevalence rate was 220/1,00,000(range : 44-843/1,00,000).
The incidence rate of stroke in India was estimated to be 13/1,00,000 in a study
done at Vellore on a population sample of 2,58,576 followed over two years,
while another study conducted at Rohtak found the stroke incidence to be
33/1,00,000 (27/1,00,000 for first ever stroke). The stroke risk increases steeply as
the age advances. In a study from Kashmir, prevalence rate of stroke was 41 per
1,00,000 population in the age range of 15-39 years, which increased to 1,075 per
1,00,000 for the age group of 50-59 years. The posterior circulation, unlike the intracranial portions of the anterior circulation,
is prone to atherosclerosis as much as other systemic arteries. In the case of one
vertebral artery being occluded, collateral flow comes from the opposite vertebral
artery, from muscular cervical artery branches, and from posterior communicating
artery.
The intracranial branches of the vertebral artery and basilar artery were minutely
studied and a syndrome was described for each prompting a cynic to remark the
neurologic equivalent of Hall of Fame is a brainstem eponym.
AIM OF THE STUDY:
To study the demographic profile and symptoms
To study the risk factors
To study the pattern of posterior circulation stroke
To prognosticate the posterior circulation stroke based on clinical and
radiological findings. CONCLUSION:
All patients with brain ischemia deserve full evaluation of their brain for vascular
lesions. With the advent of newer techniques, MRI with DW imaging, MRA, extra
cranial and transcranial doppler studies it is possible to investigate the brain and
stroke mechanisms quickly and noninvasively.
Cardiac investigations are just as important in patients with posterior circulation
ischemia, because a considerable number of posterior circulation infarcts are cardio
embolic