Case 5-2019: A 48-Year-Old Woman with Delusional Thinking and Paresthesia of the Right Hand

This case report describes a 48 year old woman presenting with delusional thinking and transient paresthesia of the right hand. Initial psychiatric evaluation suggested schizophrenia, but laboratory tests revealed severe vitamin B12 deficiency (67 pg/mL) with elevated homocysteine (93.0 μmol/L) and methylmalonic acid (13.58 μmol/L) levels, consistent with pernicious anemia. The patient’s neuropsychiatric symptoms, including disorganized thought processes and persecutory delusions, were attributed to the metabolic disorder. Treatment with parenteral vitamin B12 led to resolution of neurologic symptoms, though her psychiatric condition required additional management with valproic acid and olanzapine. The case highlights the challenges of diagnosing medical conditions in patients with severe mental illness and underscores the importance of screening for reversible causes of psychosis, such as nutritional deficiencies.

This case report describes a 48 year old woman presenting with delusional thinking and transient paresthesia of the right hand. Initial psychiatric evaluation suggested schizophrenia, but laboratory tests revealed severe vitamin B12 deficiency (67 pg/mL) with elevated homocysteine (93.0 μmol/L) and methylmalonic acid (13.58 μmol/L) levels, consistent with pernicious anemia. The patient’s neuropsychiatric symptoms, including disorganized thought processes and persecutory delusions, were attributed to the metabolic disorder. Treatment with parenteral vitamin B12 led to resolution of neurologic symptoms, though her psychiatric condition required additional management with valproic acid and olanzapine. The case highlights the challenges of diagnosing medical conditions in patients with severe mental illness and underscores the importance of screening for reversible causes of psychosis, such as nutritional deficiencies.