Stroke (Ischemic or Hemorrhagic): The combination of sudden onset dizziness, headache, unilateral weakness, and abnormal sensation strongly suggests a stroke. The left-sided weakness and abnormal sensation are classic signs of a neurological deficit, which is a hallmark of stroke.

Transient Ischemic Attack (TIA): Often referred to as a "mini-stroke," TIA presents with similar symptoms to a stroke but resolves within 24 hours. The symptoms can be identical to those of a stroke, making it crucial to monitor the patient closely.
Migraine with Aura: Some migraines are accompanied by an aura, which can include neurological symptoms such as weakness, numbness, and visual disturbances. While less common, migraines can cause significant disability and may mimic more serious conditions.
Multiple Sclerosis (MS): MS is an autoimmune disease that affects the brain and spinal cord, leading to a wide range of neurological symptoms, including weakness, numbness, and vision problems. The relapsing-remitting nature of MS can sometimes make diagnosis challenging.

Subarachnoid Hemorrhage: A life-threatening condition caused by bleeding into the space surrounding the brain, often presenting with a sudden, severe headache (thunderclap headache), which can be accompanied by other symptoms like dizziness and weakness.
Brain Tumor: Although less common, brain tumors can present with a variety of neurological symptoms depending on their location, including headaches, weakness, and sensory disturbances. Early diagnosis is crucial for treatment.
Vascular Malformations (e.g., Arteriovenous Malformation): These are abnormal connections between arteries and veins, which can cause a range of symptoms including headache, weakness, and seizures, depending on their location and whether they bleed.

Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like episodes (MELAS): A rare mitochondrial disorder that can cause stroke-like episodes, among other symptoms, due to the dysfunction of mitochondria, the energy-producing structures within cells.
CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy): An inherited condition that affects the blood vessels in the brain, leading to subcortical strokes and dementia. It's a rare cause of stroke and dementia in younger adults.
Neurosarcoidosis: A condition where sarcoidosis, an inflammatory disease, affects the nervous system, leading to a wide range of neurological symptoms, including weakness, numbness, and headache, depending on the areas of the nervous system involved.