Normal Pressure Hydrocephalus and Sleep Apnea
Normal Pressure Hydrocephalus and Sleep Apnea
Normal-pressure hydrocephalus is associated with increases in the intracranial pressure
 during the night sleep. Sleep apnea also increases the intracranial pressure during the
 apneic spells. When patients are operated the distal part of the shunt is inserted inside the
 abdominal cavity, which pressure also increases during the sleep apnea episodes. this is
 particularly important considering that the recumbent position used to sleep further
 increases the intraabdominal pressure and that impairs the CSF drainage through the shunt
 system. The purpose of this study is to analyze the intracranial and intraabdominal pressures
 during the sleep, particularly during the sleep apnea episodes to see which shunt should be
 used, to which cavity should be drained (peritoneum or heart) and if correcting the sleep
 apnea has some positive result on the hydrocephalus symptoms.
Chronic hydrocephalus in adults, also known as normal pressure hydrocephalus or normal
 pressure hydrocephalus, occurs with the classic Hakim-Adams triad, gait ataxia, or "magnetic
 gait", urinary incontinence and dementia.

 Most of the cases have an idiopathic origin and are the only potentially reversible cause of
 dementia with surgical treatment (by shunting the cerebrospinal fluid or CSF from the lateral
 ventricles or the thecal sac to the peritoneal cavity or the right atrium), so it is
 especially important to diagnose it and treat it properly.

 Unfortunately, and despite all the diagnostic arsenal, the results of treatment using
 cerebrospinal fluid shunts (lumbo-peritoneal or ventricle-peritoneal), even in the best
 series, show 20-25% of poor results. These poor results have been attributed to many factors,
 including associated cerebral vascular pathology problems, co-existing dementia symptoms not
 always well diagnosed, Parkinson's disease, and, lastly, alterations in ventilatory rhythm.
 during the night, specifically obstructive sleep apnea or OSA.

 In reality, the name of normotensive hydrocephalus or hydrocephalus at normal pressure is
 inaccurate because the intracranial pressure does rise and very markedly during sleep,
 particularly during the REM phase of sleep. What is no longer so well known is because of
 such significant increases in intracranial pressure occur. One possible explanation would be
 that obstructive sleep apnea causes increased intracranial pressure. But it remains to be
 clarified whether all patients with adult chronic hydrocephalus have sleep apnea, the
 mechanism of action, and to what extent the treatment of hydrocephalus acts on sleep apnea
 and vice versa.

 Another aspect to consider is that the cerebrospinal fluid shunts work by the pressure
 gradient between the intracranial cavity and the cavity into which the cephalo-spinal fluid
 is drained66, usually the peritoneal fluid. During sleep apnea, there should be an increase
 in intra-abdominal pressure, which would result in the ventricle-peritoneal and
 lumbo-peritoneal shunts working suboptimally precisely at the time of day when they are most
 needed, that is when intracranial pressure increases. But this correlation has never been
 investigated or at least there are no publications about it.

 Therefore, it is necessary to know the relationship between intracranial pressure, sleep
 apnea, and intra-abdominal pressure at night. With these data, it will be possible to better
 understand the dynamics of the circulation of the cerebrospinal fluid during the night (when
 it is more pathological in chronic hydrocephalus in adults), what type of bypass valve is the
 most indicated (whether or not it must have an anti-system siphon if it must be a
 gravitational or flow valve) and in which patients the implantation of a ventricle-atrial
 shunt may be an option to consider.
Inclusion Criteria:

 -  Clinical condition compatible with normal-pressure hydrocephalus

 Exclusion Criteria:

 -  Cerebral vascular disease

 -  Dementia not due to normal-pressure hydrocephalus

 -  Parkinson's disease