A Case Report of Nonketotic Hyperglycemic Seizures: A Diagnostic Dilemma

Abstract

Nonketotic hyperglycemia (NKH) is a rare but serious complication of uncontrolled diabetes mellitus that occurs acutely with a mortality rate of more than 50%. This condition presents with a clinical syndrome consisting of profound hyperglycemia, hyperosmolality, and dehydration. Infrequently, the patients also present with seizure activity. The most common types of seizures observed in this condition are focal seizures, as opposed to the generalized seizures observed in hypoglycemia-induced seizures. Though various hypotheses tried to explain NKH-induced seizure activity, the actual mechanism remains unknown. The treatment modalities include the management of hyperglycemia and circulatory collapse. However, the role of anti-epileptics is controversial. We herein illustrate an atypical case of focal faciobrachial seizures in a young female patient, which occurred as a rare complication of NKH. A 21-year-old female was admitted with multiple jerking and spasmodic movements of the right upper limb and face, with no significant neurological findings. Past medical history was significant for uncontrolled type 2 diabetes mellitus and multiple episodes of focal seizures. On laboratory examination, serum osmolarity was 309 mOsm/L, blood glucose was 364 mg/dL, HbA1c was 12.1%, and ketone bodies were absent. MRI brain showed large subtle T2 FLAIR (T2-weighted fluid-attenuated inversion recovery) cortical hyperintensities in the left frontal, temporal, parietal, and occipital regions with subcortical hypointense areas. The EEG illustrated a background slowing and generalized spikes, polyspikes, and sharp-wave discharges with post-ictal slowing. The patient's seizures were initially refractory to insulin therapy and resolved with the use of dual anti-epileptics. Thus, to conclude, our case represents a diagnostic dilemma with MRI findings pointing towards NKH as the underlying etiology of focal seizures, with the resolution of seizures only occurring with the addition of anti-epileptics to insulin therapy.

Keywords: epilepsia partialis continua; hyperglycemic seizures; nkh-induced seizures; nonketotic hyperglycemia.

Figure 1. MRI of the brain: T2-FLAIR sequence

The T2-FLAIR image of the patient is shown. The red arrow indicates subcortical hypointensity, and the yellow arrow points to the overlying cortical hyperintensity, which are the classical MRI findings to be expected in NKH-induced seizures. NKH, nonketotic hyperglycemia; T2-FLAIR, T2-weighted fluid-attenuated inversion recovery

Figure 2. Awake EEG of the patient

The awake EEG of the patient showing generalized spikes, polyspikes, and sharp-wave discharges, with post-ictal slowing. This may be due to the secondary generalization of the seizure. EEG, electroencephalography