We report on a female patient with Tourette syndrome and a 12-month follow-up after chronic deep brain stimulation in the globus pallidus internus which resulted in excellent remission of motor and vocal tics.
T rigeminal neuralgia (TN) is characterized by recurrent episodes of intense and lancinating pain localized to the sensory supply areas of the fifth cranial nerve (CN V), which is also known as the trigeminal nerve. 11 The most frequent cause of TN is mechanical irritation of the nerve within a vulnerable zone that extents for about 4 to 5 mm from the point of transition from the peripheral (derived from Schwann cells) to the central myelin (derived from the oligodendroglia) (i.e., transition zone) to the most proximal aspect, where the nerve enters the pons (i.e., root entry zone [REZ]). 24,25,31,32 It is widely believed that direct arterial contact causes pulsatile, repetitive trauma that leads to focal axonal degeneration and demyelination processes within this vulnerable site. 9,13,25 These structural alterations facilitate ephaptic neurotransmissions that cause pain upon common triggers such as chewing or tactile sensations.11 Most frequently, neurovascular compression is caused by a direct anatomical relation with the superior cerebellar artery (SCA) (60%-90%), followed by the anterior inferior cerebellar aBBreViatiONS AD = axial diffusivity; ADC = apparent diffusion coefficient; AICA = anterior inferior cerebellar artery; CE = contrast enhanced; CN = cranial nerve; DTI = diffusion tensor imaging; FA = fractional anisotropy; FIESTA = fast imaging employing steady-state acquisition; MRA = MR angiography; MVD = microsurgical decompression; PICA = posterior inferior cerebellar artery; RD = radial diffusivity; REZ = root entry zone; ROI = region of interest; SCA = superior cerebellar artery; TN = trigeminal neuralgia. OBJectiVe In this prospective study diffusion tensor imaging (DTI) was used to evaluate the influence of clinical and anatomical parameters on structural alterations within the fifth cranial nerve in patients with trigeminal neuralgia (TN) due to neurovascular compression. methOdS Overall, 81 patients (40 men and 41 women; mean age 60 ± 5 years) with typical TN were included who underwent microsurgical decompression. Preoperative 3.0-T high-resolution MRI and DTI were analyzed in a blinded fashion. The respective fractional anisotropy (FA) and apparent diffusion coefficient values were compared with the clinical, imaging, and intraoperative data. This study was approved by the institutional review board, and written informed consent was obtained from all patients. reSultS DTI analyses revealed significantly lower FA values within the vulnerable zone of the affected trigeminal nerve compared with the contralateral side (p = 0.05). The DTI analyses also included 3 patients without clear evidence of neurovascular conflict on preoperative MRI. No differences were seen between arterial and venous compression. Lower FA values were found 5 months after symptom onset; however, no correlation was found with the duration of symptoms or severity of compression. cONcluSiONS DTI analysis allows the quantification of structural alterations, even in those patients without any discernible neurovascular contact o...
A hallmark of non-rapid eye movement sleep is the coordinated interplay of slow oscillations (SOs) and sleep spindles. Traditionally, a cortico-thalamo-cortical loop is suggested to coordinate these rhythms: neocortically-generated SOs trigger spindles in the thalamus that are projected back to neocortex. Here, we used intrathalamic recordings from human epilepsy patients to test this canonical interplay. We show that SOs in the anterior thalamus precede neocortical SOs (peak −50 ms), whereas concurrently-recorded SOs in the mediodorsal thalamus are led by neocortical SOs (peak +50 ms). Sleep spindles, detected in both thalamic nuclei, preceded their neocortical counterparts (peak −100 ms) and were initiated during early phases of thalamic SOs. Our findings indicate an active role of the anterior thalamus in organizing sleep rhythms in the neocortex and highlight the functional diversity of thalamic nuclei in humans. The thalamic coordination of sleep oscillations could have broad implications for the mechanisms underlying memory consolidation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.