**Question:** Which of the following is not seen HIV involvement of CNS -

A. Encephalopathy
B. Epilepsy
C. Migraine
D. Cerebral oedema

**Core Concept:** HIV (Human Immunodeficiency Virus) infection can lead to Central Nervous System (CNS) involvement, causing various neurological and psychiatric disorders. HIV enters the CNS through the haematogenous route or the translocation from the gut through the vagus nerve. The CNS effects can be broadly categorized into acute, subacute, and chronic stages.

**Why the Correct Answer is Right:** Migraine is a primary headache disorder characterized by unilateral, pulsating headaches with associated symptoms like nausea, vomiting, and photophobia. Migraine is not specific to HIV infection and can occur in various other conditions as well. HIV-related migraine is a rare phenomenon, making it less likely to be seen in HIV involvement of the CNS.

**Why Each Wrong Option is Incorrect:**

A. Encephalopathy: This term refers to a general disturbance of brain function, often seen in HIV infection due to neuronal damage and inflammation. It is a correct answer, as it is a common manifestation of HIV CNS involvement.

B. Epilepsy: Seizures are more commonly associated with HIV infection, but the specific type of seizures (e.g., complex partial seizures) can be confused with other neurological disorders like stroke or encephalitis. However, the presence of HIV infection is not a contraindication to the diagnosis of epilepsy.

C. Cerebral oedema: HIV-related cerebral oedema is a well-known complication of HIV infection and can be life-threatening. It typically presents as a space-occupying lesion on imaging studies and can manifest as altered mental status or focal neurological deficits.

**Clinical Pearl:** HIV-induced neurological disorders can present with a broad spectrum of symptoms and signs, making a thorough clinical evaluation and imaging studies crucial for diagnosis and management.

**Correct Answer:** Migraine (Option C) is not seen in HIV infection of the CNS, while the other options (Encephalopathy, Epilepsy, and Cerebral oedema) are more commonly associated with HIV involvement of the CNS.