Role of High Frequency Oscillations of Somatosensory Evoked Potentials in Deciphering Pathophysiology of Migraine

Background  Habituation deficit is considered as a neurophysiological abnormality among migraineurs in the interictal period. For clear comprehension and clarity about the mechanism underlying habituation in migraine, a sophisticated method, i.e., high frequency oscillations (HFOs) evoked potentials, have been utilized. However, studies pertaining to this in the Indian context are rare.

Objective  The aim of the study is to determine the utility of HFO of somatosensory evoked potential (SSEP) in deciphering the pathophysiology of migraine.

Materials and Methods  Sixty subjects including 30 migraineurs in the interictal period and 30 healthy controls were considered for the study. Median nerve SSEP was recorded in patients and controls by standard protocols. HFO was extracted offline using the Digital zero-phase shift band-pass filtering at 450 and 750 Hz. The early and late HFOs were determined with respect to the N20 peak and were compared between the groups.

Results  Of total 30 migraineurs, 18 had hemicranial headache and 12 had holocranial headache. N20 latency, P25 latency, N20 onset to peak amplitude, and N20 onset to P25 amplitude were comparable in migraineurs and controls. The intraburst frequency of early HFOs in migraineurs was significantly higher ( p = 0.04), whereas the peak-to-peak amplitude was significantly lower ( p = 0.001).

Conclusion  Early HFOs on SSEP represent the thalamocortical excitatory drive in migraineurs. Overall, the study reports that reduced amplitude of early HFOs in the interictal period suggest reduced thalamocortical drive in migraineurs.

Acute seizures in cerebral venous sinus thrombosis: What predicts it?

BACKGROUND

Seizures are the presenting feature of cerebral venous sinus thrombosis (CVST) in 12-31.9% of patients. 44.3% of patients have seizures in the early stage of the disease. Acute seizures (AS), refers to seizures which take place before the diagnosis or during the first 2 weeks afterward.

OBJECTIVE

To report the predictors of acute seizures in cerebral venous sinus thrombosis (CVST).

METHODS

100 patients with CVST were included in the study. The occurrence of acute seizures was noted. The predictors of acute seizure were evaluated by univariate analysis including the demographic (gender, age), clinical (headache, focal neurological deficit, papilloedema, GCS score), type and number of risk factors, MRI findings (Type of lesion: hemorrhagic infarction or hematoma, location of lesion) and MRV findings (superficial or deep sinus, cortical veins).

RESULTS

A total of 46 patients had acute seizures. On univariate analysis, altered mental status (p<0.001), paresis (p=0.03), GCS score <8 (p=0.009), hemorrhagic infarct on imaging (p=0.04), involvement of frontal lobe (p=0.02), superior sagittal sinus (p=0.008), and high D-dimer levels (p=0.03) were significantly associated with acute seizure. On multivariate analysis, the hemorrhagic infarct on MRI and high D-dimer was independently predictive for early seizure.

CONCLUSION

The predictive factors for the acute seizures are altered mental status (GCS<8), focal deficits, hemorrhagic infarct, involvement of frontal lobe and superior sagittal sinus with high D-dimer levels.

Newborn with congenital facial palsy and bilateral anotia/atresia of external auditory canal: Rare occurrence

Congenital facial palsy (CFP) is clinically defined as facial palsy of the seventh cranial nerve which is present at birth or shortly thereafter. It is generally considered to be either developmental or acquired in origin. Facial palsy of developmental origin is associated with other anomalies including those of pinna and external auditory canal, which range from mild defects to severe microtia and atresia. We report a 2-day-old male newborn that had right CFP with bilateral anotia and atresia of external auditory canals which is rare.