Differential Diagnosis for Drifting when Walking and Episodes of Amnesia

Single Most Likely Diagnosis

• Alzheimer's Disease: This is a common cause of progressive memory loss and cognitive decline, which could explain the episodes of amnesia. Drifting when walking could be related to spatial disorientation, a symptom often seen in Alzheimer's patients.

Other Likely Diagnoses

• Vascular Dementia: Similar to Alzheimer's, vascular dementia can cause memory loss and cognitive decline. Episodes of amnesia could be due to small strokes or changes in brain blood flow. Drifting while walking might be due to difficulties with balance and coordination.
• Frontotemporal Dementia: This condition affects the front and temporal lobes of the brain and can cause significant changes in personality, behavior, and language, as well as memory loss. Spatial awareness and motor skills could be affected, leading to drifting when walking.
• Normal Pressure Hydrocephalus (NPH): Characterized by the triad of gait disturbance, dementia, and urinary incontinence, NPH could explain the drifting when walking due to gait disturbances and episodes of amnesia due to cognitive decline.

Do Not Miss Diagnoses

• Transient Ischemic Attacks (TIAs): These "mini-strokes" can cause temporary symptoms similar to a stroke, including confusion, memory loss, and difficulty with coordination and balance, which could explain both drifting when walking and episodes of amnesia. TIAs are a warning sign for a future stroke, making prompt diagnosis critical.
• Seizure Disorders: Certain types of seizures, especially complex partial seizures, can cause episodes of amnesia. Post-ictal confusion and disorientation could lead to drifting when walking.
• Brain Tumors: Both primary and metastatic brain tumors can cause a variety of neurological symptoms depending on their location, including memory loss, confusion, and difficulties with balance and coordination.

Rare Diagnoses

• Creutzfeldt-Jakob Disease: A rare, degenerative, fatal brain disorder that can cause memory loss, behavioral changes, poor coordination, and visual disturbances. Drifting when walking could be due to ataxia, a symptom of this disease.
• Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, characterized by cognitive decline, seizures, and gait disturbances, among other symptoms. Episodes of amnesia and drifting when walking could be part of the presentation.
• Whipple's Disease: A rare, systemic bacterial infection that can cause malabsorption, weight loss, and a variety of neurological symptoms, including memory loss, confusion, and difficulties with coordination and balance.