Differential considerations of Tcd pulsatility (Gosling’s) and resistance (Pourcelot) indices after Avm surgery

Abstract

A 29-year-old man previously healthy described the
worst headache of his life prior to admission where a CT
scan was performed at the local emergency department
(Figure 1a). This showed an acute intraparenchymal
hemorrhage of 5.7 cm × 3.4 cm × 5.7 cm dimensions, or
~54 cm3
volume [1]. The patient had acute right-sided
hemiplegia and aphasia and a NIHSS stroke of 16. The
patient underwent an acute digital subtraction angiogram
(DSA) which revealed a Spetzler Martin grade 3 arteriovenous malformation (AVM) (Figure 1b) [2]. The
Figure 1a.
patient was transferred to our facility where he underwent acute left-sided craniotomy, hematoma evacuation,
AVM resection, and clipping. Because of the concerns
about some blood being seen on the cortex and the theoretical concerns about arterial subarachnoid hemorrhage
(Figure 1c) occurring from his AVM, transtemporal
transcranial Doppler imaging was performed to screen
for large vessel vasospasm [3,4] which are shown in
Figure 1d. Although mean flow velocities (MFVs) of
the left MCA-M1 were not indicative of vasospasm (i.e.,
>120–200 cm/s), the pulsatility (Gosling’s) index (PI)
and resistance (Pourcelot) index (RI) were markedly
abnormal on the left compared with the right, and raised
the question about downstream resistance or poor intracranial compliance (Table 1, differential of raised PI and
RI) based on TCD differential [5]. However, on careful
review of the DSA, the patient’s AVM had a high-flow
left MCA-M2 branch which after surgery (Figure 1e and
f) was dramatically reduced in flow.