Thrombotic thrombocytopenic purpura (TTP) is a rare thrombomicroangiopathy caused by deficiency of ADAMTS13. Acute neurological involvement is well described, but its long-term impact requires evaluation. One-hundred thirty-one patients, following an acute TTP event, with severe headache or neurological symptoms had a cerebral MRI. Fifty-six percent had abnormal imaging, more commonly in patients with neurological symptoms than headaches only (80% vs. 18%, P < 0Á0001). In remission, 27% (n = 35) reported persistent cognitive symptoms: specifically, impaired memory (66%), difficulty concentrating (26%), and word-finding difficulties not secondary to an acute stroke (26%). Sixty-five percent also reported depression and 55% reported anxiety, regardless of presenting neurology. The frontal lobe was disproportionally affected in patients with marked intellectual impairment, seen in 67% of patients compared to 19% of patients without intellectual impairment (P = 0Á002). The primary MRI finding in these patients was hyperintense white matter lesions. An abnormal MRI was associated with a lower median verbal IQ (85 vs. 99, P = 0Á02) and performance IQ (83 vs. 100, P = 0Á02). In conclusion, neurological symptoms are frequently associated with an abnormal cerebral MRI scan, and white matter frontal lobe lesions are particularly significant, leading to marked intellectual impairment. Anxiety and depression were evident in over half of patients, regardless of neurological involvement at presentation.

BackgroundSodium valproate is a commonly used anticonvulsant. It is widely recognized that valproate can cause hyperammonemia, particularly in people with underlying liver disease. Patients with urea cycle disorders are genetically predisposed to this adverse event and can develop severe hyperammonemia if given valproate.This can occur even if liver functions tests and plasma concentration of valproate are normal, highlighting the importance of checking ammonia levels in any patient presenting with encephalopathy. Specific treatment for hyperammonemia must be implemented promptly.Case presentationA 22-year-old white British man with a history of epilepsy post head trauma presented with subacute encephalopathy 4 weeks after the introduction of sodium valproate. His ammonia levels were not checked until 48 hours into his presentation and were found to be elevated. He initially responded to treatment of his hyperammonemia and the raised levels were attributed to sodium valproate. However, as his ammonia levels continued to rise, further investigation led to a diagnosis of ornithine transcarbamylase deficiency.ConclusionsOrnithine transcarbamylase deficiency is the most common of the urea cycle disorders. This case highlights both the importance of checking ammonia levels early and considering the diagnosis of this X-linked disorder in patients with raised ammonia, as these have implications both for the patient’s acute and further management, and for family screening.

We review the obstetric cases reported so far and discuss diagnostic matters and current management strategies.