External hydrocephalus treatment

Considering the few studies that have dealt with the effect of treatment of external hydrocephalus, it is obvious that more knowledge is needed. For now, the apparent diversity in results and opinions probably reflects a similar variety in clinical courses and patients, this again reflecting the different etiologies and partial inheritance often seen as well as the differences in what is regarded as “normal.” A good way to answer some of these questions is to carry out a larger population-based (retrospective) study, comparing treated (shunted) and untreated children with external hydrocephalus and focusing on developmental outcome on long-term follow-up, including the use of standardized neuropsychological tests. By doing this, it may be possible to reveal subtypes/subgroups of patients with different outcome prognoses, hence in need of different initial managements. Surgical indication could, for instance, be determined by the initial radiological presentation (width of subarachnoid space, diffusion-weighted MRI), by a thorough neuropsychological investigation, or maybe by a combination of all signs and tests available (ICP, CSF flow, etc.) ¹⁾.

Several studies describe temporary acetazolamide treatment lasting for 1–2 months, resulting in a gradual reduction of excessive head growth. Furthermore, Roshan et al. used acetazolamide combined with mannitol in four patients who presented with vomiting, irritability, and a bulging fontanel. The patients responded well.

Acetazolamide and furosemide have been recommended for mild hydrocephalus of the newborn and in infants , but based on large, randomized trials it is not recommended for the treatment of posthemorrhagic ventricular dilatation in infancy ²⁾.

7 patients were subjected to exploratory craniotomy which disclosed a deep arachnoid space. 2 patients were shunted. All follow-up CT examinations showed normal conditions.

Andersson et al., suggest that infants with clinical signs of hydrocephalus and CT picture of external hydrocephalus should not be treated with shunt. The widening of the subarachnoidal space will normalize. The rate of headgrowth will also normalize ³⁾.