Stroke is an acute neurologic injury occurring as a result of vascular pathological processes which manifest either as brain infarction or haemorrhage. Stroke is the second most common cause of mortality and the third most common cause of disability worldwide. General clinical features include weakness or paralysis of one half of the body, dizziness, vertigo, confusion, slurred speech, drooping of the face on one side, loss of coordination, and visual problems such as blindness or diplopia.

Stroke is broadly classified into three categories: ischemic stroke, haemorrhagic stroke, and subarachnoid haemorrhage. Ischemic stroke occurs due to blockage of a blood vessel which limits blood supply to the brain. Ischemic strokes are further divided into two groups.

Thrombotic strokes are caused by a blood clot that develops in the blood vessels inside the brain. Embolic strokes are caused by a blood clot or plaque debris that develops elsewhere in the body and then travels to the brain through the bloodstream.

The global incidence and prevalence of stroke in 2023 is approximately 25 percent, whereas ischemic stroke is 0.15 percent per one lakh population according to the American Association of Neurology. In India, the incidence and prevalence of stroke is 0.145 percent, whereas ischemic stroke is 0.049 percent per one lakh population as per the Indian Academy of Neurology.

Risk factors for ischemic stroke include high blood pressure, diabetes mellitus, hyperlipidemia, excessive alcohol intake, cigarette smoking, obesity, high plasma fibrinogen levels, and cardiac lesions such as atrial fibrillation, mitral valve prolapse, valvular stenosis, congestive cardiac failure, and infective endocarditis.

Clinical presentation of ischemic stroke commonly includes sudden onset weakness or paralysis of one side of the body. Unilateral weakness is the classical presentation of stroke and rarely of cerebral venous thrombosis. The weakness progresses rapidly and follows a hemiplegic pattern.

Speech disturbances such as dysphasia and dysarthria are common. Dysphasia indicates damage to the frontal or parietal lobe, whereas dysarthria indicates incoordination of the face, pharynx, lips, tongue, or palate.

Visual loss may occur due to unilateral optic ischemia, known as amaurosis fugax if transient, caused by impaired blood flow in the internal carotid or ophthalmic artery, leading to monocular blindness. Cerebellar involvement may present as acute ataxia with associated brainstem features such as diplopia and vertigo. Headache is common in acute ischemic stroke but is rarely a dominant feature.

Cognitive effects of stroke include dysphasia, dysgraphia, dyslexia, dyscalculia, aprosody, impaired spatial orientation, anxiety, depression, and emotional lability resulting in inappropriate crying or laughter triggered by minor emotional stimuli.

Pathophysiology of ischemic stroke depends on the degree of cerebral blood flow impairment and the duration before reperfusion. When cerebral blood flow falls from normal levels of approximately 50 ml per 100 grams of brain tissue per minute to less than 10 ml per 100 grams per minute, neuronal cell death occurs rapidly.

Between the ischemic core and normally perfused tissue lies the ischemic penumbra, a region of moderately reduced blood flow dependent on collateral circulation. Neurons in this region are hypoxic and functionally inactive but remain viable. Without reperfusion, secondary biochemical cascades occur, including glutamate release, NMDA receptor activation, sodium and calcium influx, free radical formation, and eventual neuronal destruction. This underlines the concept that time is brain.

Differential diagnosis of stroke includes space occupying lesions such as subdural hematoma, tumors, cerebral abscess, and granuloma. Multiple sclerosis may mimic stroke with hemiplegia or brainstem symptoms. Hysteria is rare but should be considered when signs are inconsistent with organic disease.

Management of ischemic stroke primarily involves tissue plasminogen activator to dissolve the clot. Time is the most critical factor. Treatment options include intravenous thrombolysis and mechanical thrombectomy. Aspirin is used as an antiplatelet agent, with other agents such as clopidogrel and dipyridamole used later.

Anticoagulants such as warfarin, apixaban, dabigatran, edoxaban, and rivaroxaban prevent clot formation and are used for long term management. Surgical options include carotid endarterectomy and carotid angioplasty with stenting.

Physiotherapy and rehabilitation include mobility training, motor skill exercises, and range of motion therapy.

In Ayurveda, Pakshaghata is an important vata vyadhi described under vataja nanatmaja vyadhi and mahavata vyadhi. It may occur due to dhatu kshaya or marga avarana. Pakshaghata refers to loss of function of one half of the body.

Nidana of Pakshaghata include ahara such as ruksha, sheeta, laghu ahara, akala bhojana, langhana, and ama. Vihara includes ati vyayama, ati prajagara, vega dharana, sheeghra yana, ati vyavaya, vishamopachara, ati dosha sravana, ati asruk sravana, ati langhana, dukha shayya, asana, diva swapna, and abhighata. Manasika nidana include chinta, shoka, krodha, and bhaya. Other causes include roga, marma abhighata, and dhatu samkshaya.

Lakshanas of Pakshaghata include loss of voluntary movement on one side of the body, loss of sensation, contracture and spasticity of limbs, falling down, affection of one side of the body, abnormalities of blood vessels and ligaments, speech impairment, looseness of joints especially the shoulder, pain, and pricking sensations.

Anubandha lakshanas include pittanubandha such as burning sensation, feverishness, and delirium, and kaphanubandha such as cold sensation, swelling, and heaviness.

Samprapti of Pakshaghata involves aggravated vata causing constriction of vessels and ligaments, leading to paralysis of one side of the body. Excessively aggravated vata within dhamanis moves in abnormal directions causing loss of function, unconsciousness, collapse, or even death.

Shamana chikitsa helps in pacifying vitiated doshas. Oral formulations include Rasnadasamooladi kwatha, Sahacharadi kwatha, Narayana taila, Prasarini taila, Rasnadi guggulu, Vatagajankusha rasa, Mahavatagajankusha rasa, Chintamani rasa, Brihat vatachintamani rasa, Laghu ananda rasa, Brahmi ghrita, Kalyanaka ghrita, Vacha ghrita, Mahapaisachika ghrita, Shankhapushpi, Ashwagandha lehyam, and Saraswati churnam.

Chikitsa sutra includes snehana and swedana, mridu shodhana, anuvasana and asthapana basti, shiro basti, abhyanga, snana, upanaha swedana, and bala taila anuvasana.

Snehana and swedana cause utkleshana and draveekarana of doshas. Virechana eliminates doshas through the gastrointestinal tract and acts on pitta, rakta, sira, and kandara. Shiras is the main adhisthana of Pakshaghata and pranavata governs higher brain functions.

Nasya karma is the principal procedure acting on urdhva jatrugata vikaras. Drugs administered through the nose reach the shira region, remove morbid doshas, and pacify vata simultaneously. Nasya with Karpasasthyadi taila produces local hyperemia of nasal mucosa, enhancing absorption. Being lipid in nature, the drug can act effectively on the central nervous system, establishing a close relationship between shiras and nasa.

Virechana is considered the best treatment for Pakshaghata. Tilvaka ghrita siddha virechana yoga is described as a safe and effective virechana formulation for Pakshaghata.