Cerebrospinal fluid diversion in patients with enlarged Virchow-Robin spaces without ventriculomegaly

MDS-UDPRS-III in the diagnosis of idiopathic Normal Pressure Hydrocephalus and identification of candidates for Ventriculo-Peritoneal Shunting surgery. Results from a retrospective large cohort of patients

OBJECTIVES

To evaluate the entity of extrapyramidal signs, characterize them and evaluate the dynamics of change by the mean of MDS-UPDRS-III in iNPH patients after the TT to determine if this tool may help the diagnosis of iNPH and the identification of candidates for Ventriculo-Peritoneal Shunting.

MATERIALS AND METHODS

We retrospectively collected data from 120 patients with the initial diagnosis of possible iNPH; they underwent neurological examination by the means of MDS-UPDRS-III and other scales before and after Tap Test (TT). They were then classified as defined iNPH (57), probable iNPH (35), and NOT-iNPH (28) based on the clinical response after the Tap Test and VPS.

RESULTS

After the Tap Test, defined and probable iNPH groups improved by 3.35 (2.57-4.12, p < 0.001) and 3.43 (2.43-4.4, p < 0.001) points on MDS-UPDRS-III respectively; NOT-iNPH did not improve significantly on MDS-UPDRS-III and on any other variable studies. Defined iNPH also shifted significantly from asymmetric prevalence of symptoms to a more symmetric form (from 70% before to 57% after).

CONCLUSION

extrapyramidal signs improved significantly after the Tap Test in definite and probable iNPH patients. MDS-UPDRS-III may be a useful complementary tool in the diagnosis of iNPH and identification of candidates for Ventriculo-Peritoneal Shunting.

Case report: A multiple sclerosis patient with imaging features of glymphatic failure benefitted from CSF flow shunting

The derangement of CSF circulation impacts the functions of the glymphatic-lymphatic system (G-Ls), which regulates solute trafficking and immune surveillance in the CNS. The G-Ls failure leads to the dysregulation of clearance of waste molecules in the brain and to an altered CNS immune response. The imaging features of dilated perivascular spaces imply the impairment of the G-Ls. We report on the case of a patient with primary progressive multiple sclerosis and dilatation of perivascular spaces, who transiently improved after CSF shunt diversions. The underlying mechanisms remain to be determined and at this stage, it is not possible to link CSF diversion to an effect on MS pathology. However, this observation provides the rationale to incentivize research in the largely unknown area of CSF dynamic disturbances on G-Ls failure and ultimately in neurodegeneration.

The putative glymphatic signature of chronic fatigue syndrome: A new view on the disease pathogenesis and therapy

The underlying pathophysiology of chronic fatigue syndrome remains incompletely understood and there are no curative treatments for this disorder at present. However, increasing neuroimaging evidence indicates that functional and structural abnormalities exist in the brains of chronic fatigue syndrome patients, suggesting that the central nervous system is involved in this disorder and that at least some chronic fatigue syndrome patients may have an underlying neurological basis for their illness. In the present paper, we speculate that glymphatic dysfunction, causing toxic build up within the central nervous system, may be responsible for at least some cases of chronic fatigue syndrome. We further postulate that cerebrospinal fluid diversion such as lumboperitoneal shunting may be beneficial to this subgroup of patients by restoring glymphatic transport and waste removal from the brain. Although recent evidence indicates that at least some chronic fatigue syndrome patients may benefit from cerebrospinal fluid drainage, further studies are needed to confirm this finding and to determine whether this can be attributed to enhancement of glymphatic fluid flow and interstitial fluid clearance. If confirmed, this could offer promising avenues for the future treatment of chronic fatigue syndrome. Clearly, given the relative invasive nature of cerebrospinal fluid diversion, such procedures should be reserved for chronic fatigue syndrome patients who are severely debilitated, or for those with severe headaches. Anyhow, it seems worthwhile to make every effort to identify new therapies for patients who suffer from this devastating disease, especially given that there are currently no effective treatments for this condition.

Comparison of ventricular drain location and infusion test in hydrocephalus

OBJECTIVES

Suspected cerebrospinal fluid shunt (CSF) dysfunction in hydrocephalic patients poses a diagnostic uncertainty. The clinical picture can be non-specific and CT imaging alone is not always pathognomonic. Infusion tests are an increasingly used investigation for real-time hydrodynamic assessment of shunt patency. We report the correlation between infusion test results with the quality of ventricular drain placement on CT scans in a large retrospective group of hydrocephalic patients.

MATERIALS & METHODS

Three hundred and six infusion test results performed in 200 patients were correlated with 306 corresponding CT head scans. Nominal logistic regression was used to correlate shunt catheter position on CT imaging to patency of ventricular drain as determined by infusion tests.

RESULTS

Infusion test results of shunt patency are statistically congruent with the analysis of shunt catheter position on CT head scans. Catheter tips completely surrounded by either parenchyma or CSF on CT imaging are strongly associated with evidence of occlusion or patency from infusion tests, respectively (χ² = 51.68, P < 0.0001, n = 306 and χ² = 31.04, P < 0.0001, n = 306).

CONCLUSIONS

The most important anatomical factor for shunt patency is the catheter tip being completely surrounded by CSF. Infusion tests provide functional and reliable assessment of shunt patency in vivo and are strongly correlated with the position of the ventricular catheter on CT imaging.

Influence of general anaesthesia on slow waves of intracranial pressure

OBJECTIVE

Slow vasogenic intracranial pressure (ICP) waves are spontaneous ICP oscillations with a low frequency bandwidth of 0.3-4 cycles/min (B-waves). B-waves reflect dynamic oscillations in cerebral blood volume associated with autoregulatory cerebral vasodilation and vasoconstriction. This study quantifies the effects of general anaesthesia (GA) on the magnitude of B-waves compared to natural sleep and conscious state.

MATERIALS AND METHODS

The magnitude of B-waves was assessed in 4 groups of 30 patients each with clinical indications for ICP monitoring. Normal pressure hydrocephalus patients undergoing Cerebrospinal Fluid (CSF) infusion studies in the conscious state (GROUP A) and under GA (GROUP B), and hydrocephalus patients undergoing overnight ICP monitoring during physiological sleep (GROUP C) were compared to deeply sedated traumatic brain injury (TBI) patients with well-controlled ICP during the first night of Intensive Care Unit (ICU) stay (GROUP D).

RESULTS

A total of 120 patients were included. During CSF infusion studies, the magnitude of slow waves was higher in conscious patients (

GROUP A

0.23+/-0.10 mm Hg) when compared to anaesthetised patients (

GROUP B

0.15+/-0.10 mm Hg; p = 0.011). Overnight magnitude of slow waves was higher in patients during natural sleep (GROUP C: 0.20+/-0.13 mm Hg) when compared to TBI patients under deep sedation (GROUP D: 0.11+/- 0.09 mm Hg; p = 0.002).

CONCLUSION

GA and deep sedation are associated with a reduced magnitude of B-waves. ICP monitoring carried out under GA is affected by iatrogenic suppression of slow vasogenic waves of ICP. Accounting for the effects of anaesthesia on vasogenic waves may prevent the misidentification of potential shunt-responders as non-responders.