Hydrocephalus-Associated Hyponatremia: A Review.

Hydrocephalus is the pathological accumulation of cerebrospinal fluid within the ventricles of the brain. Hydrocephalus may be broadly divided into three categories: congenital, acquired, or other. Hyponatremia, serum sodium level <135 meq/ml, may be caused by dilution (e.g. syndrome of inappropriate antidiuretic hormone (SIADH)), depletion (e.g. cerebral salt wasting (CSW)), or delusion (e.g. psychogenic water intake) etiologies. This review discusses "hydrocephalus-associated hyponatremia" as a clinical entity, distinct from SIADH and CSW. Some experts believe that in hydrocephalus patients, increased pressure on the hypothalamus leads to the release of antidiuretic hormone (ADH), which in turn causes hyponatremia. The true etiology of hyponatremia is critical to diagnose, as it will determine the treatment. So while both SIADH and CSW may result in hyponatremia, the former is treated with fluid restriction, while the latter requires fluid repletion; treating SIADH as CSW, and vice versa, will exacerbate the hyponatremia. The etiology and severity of hyponatremia will determine the management. For hydrocephalus-associated hyponatremia, treating the underlying problem (i.e. hydrocephalus) is the mainstay of therapy. Theoretically, treatment of hydrocephalus-related hyponatremia with CSF-diversion procedures should relieve the pressure on the hypothalamus, mitigating ADH production, which in turn will decrease sodium excretion and ameliorate the hyponatremia.

A Comparison of Seizure Prophylaxis: Phenytoin Versus Levetiracetam.

Phenytoin and levetiracetam are both antiepileptic drugs (AEDs) used for seizure prophylaxis. However, to date, there is a paucity of literature comparing their relative efficacies. In this narrative review, we seek to determine if there is greater advantage between the two AEDs, levetiracetam and phenytoin. Phenytoin is the more traditional AED of the two as it has been medically used for a much longer time than levetiracetam. However, levetiracetam, the newer AED of the two, has fewer side effects than phenytoin and fewer drug-drug interactions. Although past studies have aimed to compare the efficacy of phenytoin versus levetiracetam, there is no clear consensus as to if there is a clinical advantage to one over the other. Here, we have analyzed several studies published between 2013 and 2020 in the hopes of having a better understanding of which AED is more efficient in preventing seizures. Many factors can contribute to determining which AED is the better fit for patients, including pricing, risk for adverse drug effects, and level of patient monitoring. After analysis of past research, the more advantageous AED still remains unclear. Future research must be conducted that involve large patient populations, stratifying age populations, and studies analyzing cost-effectiveness to clearly determine if there is indeed a more advantageous AED between levetiracetam and phenytoin.