Establishing continuum in Transcranial Doppler characteristics of IIH, migraine and healthy controls- An exploratory study

Background: IIH is a severe form of headache that often has superimposed migraine and often it is very difficult to distinguish the two forms of headache. Intracranial hemodynamics is a relatively unexplored means of distinguishing between the two forms of headache.

Objectives: We aimed to study intracranial flow dynamics using Transcranial Doppler in patients with IIH, migraine, and normal controls.

Materials and methods: It was a hospital-based observational study that included 51 people with IIH, 87 people with migraine, and 101 healthy controls and all were subjected to TCD study after detailed clinical examination.

Results: Mean age of patients in three groups were similar with the mean age in IIH being 33.41 ± 10.75 (age in years ± SD). Vision loss was present in 66.67% of patients with IIH, and most common field defect was generalized constriction (27.5%). Neuroimaging was abnormal in 94.11% of patients of IIH with mean CSF pressure was 31.27±5.32 cm of water. Of all the TCD-measured velocities, mean flow velocity (MFV) showed a significant difference in all three groups with (p-value <0.001). The pulsatility index, both for middle cerebral arteries as well as ophthalmic arteries showed a significant difference in the three groups with the highest values in IIH patients (p-value<.001). The mean VMR in IIH (1.11±0.32) was lower than the mean VMR in migraine (1.34±0.43) as well as controls (1.49±0.46).

Conclusion: TCD parameters like MFV and PI are useful parameters that show considerable variation and can be used to differentiate between IIH and migraine.