Seizures in a Patient With Hyponatremia

Case Study

A rapid response event is initiated by a bedside nurse for a patient having seizure-like activity. On arrival of first responders, the patient was confused, however, not actively seizing. Per the bedside nurse, the patient was a 37-year-old male with a past medical history of alcohol use disorder admitted to the hospital a few hours earlier with confusion, headaches, and nausea. The nurse described right-sided jerky movements lasting 1 min, during which the patient was non-arousable. It was noted that a recent basal metabolic panel showed a sodium of 110 meq/L and an alcohol level of 350 mg/dL. His social history was notable for significant alcohol use, almost 24 beers daily. He was placed on an alcohol withdrawal assessment score; the highest he had scored was five, and he had not required any lorazepam till this time. His hyponatremia was being worked up, and he was noted to have a urine osmolality of <100. During chart review, the patient had another episode of a right-sided focal seizure lasting ~1 min.

Vital Signs

Temperature: 97.9 °F, axillary
Blood Pressure: 128/97 mmHg
Heart Rate: 96 beats per min (bpm), sinus rhythm on telemetry
Respiratory Rate: 22 breaths per min
Pulse Oximetry: 98% oxygen saturation on room air

Focused Physical Examination

A quick exam revealed a thin male lying on his back in bed. He was arousable to vocal stimuli. He was not alert or oriented and was very drowsy. A cardiovascular exam revealed a regular rate and rhythm without murmurs. His respiratory exam was notable for tachypnea, equal breath sounds, and no rhonchi or wheezes. The neurologic exam was limited because of the patient’s mental status. His right upper extremity was noted to be contracted, spontaneous movements of the left arm and both legs were seen. His skin turgor was decreased.

Interventions

A cardiac monitor was attached, and because of multiple seizures within 5 min, the patient was given 4 mg IV lorazepam, which terminated the seizures. A stat computed tomography (CT) of the head was done to rule out intracranial pathologies, and it was unremarkable. The likely differential was seizures because of hyponatremia and less likely an acute intracranial process, infection, or alcohol withdrawal. This presumptive diagnosis was based on his history, blood tests, vitals, and alcohol withdrawal assessment score. Considering this presumptive diagnosis, a stat consult was obtained from nephrology regarding hyponatremia. The patient was given a 100 mL bolus of hypertonic saline over 10 min with a goal sodium increase of 4-6 meq/L. The patient was transferred to the intensive care unit for closer monitoring of his neurological status and electrolyte levels.

Final Diagnosis

Seizures secondary to severe hyponatremia caused by beer potomania.

Symptomatic Hyponatremia

Hyponatremia is defined as a serum sodium level of less than 135 meq/L.

Hyponatremia has many causes including syndrome of inappropriate antidiuretic hormone secretion (SIADH), low effective arterial blood volume, glucocorticoid deficiency, psychogenic polydipsia, cerebral salt wasting, medication-induced hyponatremia, and beer potomania. This disorder can be classified as hypervolemic, euvolemic, and hypovolemic ( Fig. 46.1 ); the diagnostic features of these sub-classes are outside the scope of this text.