Evidence for Altered Basal Ganglia-Brainstem Connections in Cervical Dystonia

Abstract

BackgroundThere has been increasing interest in the interaction of the basal ganglia with the cerebellum and the brainstem in motor control and movement disorders. In addition, it has been suggested that these subcortical connections with the basal ganglia may help to coordinate a network of regions involved in mediating posture and stabilization. While studies in animal models support a role for this circuitry in the pathophysiology of the movement disorder dystonia, thus far, there is only indirect evidence for this in humans with dystonia.Methodology/Principal FindingsIn the current study we investigated probabilistic diffusion tractography in DYT1-negative patients with cervical dystonia and matched healthy control subjects, with the goal of showing that patients exhibit altered microstructure in the connectivity between the pallidum and brainstem. The brainstem regions investigated included nuclei that are known to exhibit strong connections with the cerebellum. We observed large clusters of tractography differences in patients relative to healthy controls, between the pallidum and the brainstem. Tractography was decreased in the left hemisphere and increased in the right hemisphere in patients, suggesting a potential basis for the left/right white matter asymmetry we previously observed in focal dystonia patients.Conclusions/SignificanceThese findings support the hypothesis that connections between the basal ganglia and brainstem play a role in the pathophysiology of dystonia.

The Role of the Trigeminal Sensory Nuclear Complex in the Pathophysiology of Craniocervical Dystonia

“…This is supported by the many studies demonstrating altered trigeminal reflexes in chronic neck pain, and migraine and cervicogenic headache in a manner remarkably similar to dystonia (Schoenen et al, 1987;Nakashima and Takahashi, 1991;Bánk et al, 1992;de Tommaso et al, 2002;Milanov and Bogdanova, 2003;Nardone and Tezzon, 2003a, b;Proietti Cecchini et al, 2003;Nardone et al, 2008). In the rat, inflammatory arthritis of the TMJ leads to sensitization of WDR neurons in the spinal trigeminal nucleus and increases the responsiveness of these neurons to further afferent input (Takeda et al, 2012).…”

“…Aberrant trigeminal reflexes are apparent in people who experience blepharospasm, and oromandibular, cranial, and cervical dystonia (Berardelli et al, 1985;Tolosa et al, 1988a, b;Nakashima et al, 1989;Alfonsi et al, 1992), with loss of reflex inhibition and increased reflex facilitation. In people with blepharospasm, and cranial and oromandibular dystonia, there is an increase in amplitude of both the early and late components of the blink reflex Schematic of an integrated network model including the TSNC in the pathophysiology of dystonia.…”

“…3A). Reduced dopamine in the substantia nigra causes an abnormally enhanced inhibitory output from the globus pallidus internus (GPI), supressing the superior colliculus and nucleus raphe magnus, and in turn disinhibiting the TSNC to potentiate trigeminal reflexes (Basso and Evinger, 1996;Basso et al, 1996). Alternately, reduction in substantia nigra and globus pallidus inhibitory modulation over the pedunculopontine nucleus may disinhibit the TSNC via cholinergic projections (Morcuende et al, 2002).…”

“…Despite the high incidence, dystonia remains poorly understood, and treatment options are limited. For craniocervical dystonia, injections of botulinum toxin are the most common treatment at present but are not effective or tolerated by all patients (Snaith and Wade, 2011;Batla et al, 2012). In this article, we review the evidence for a role of the trigeminal sensory nuclear complex (TSNC) within the wider distributed network of brain regions contributing to the pathophysiology of craniocervical dystonia.…”

Chiropractic care using a functional neurologic approach for idiopathic cervical dystonia in a 59-year-old woman

“…4 Current literature suggests that the pathophysiology of CD is a result of a www.journalchiromed.com dysfunction in the basal ganglia, substantia nigra, pontine brainstem, and cerebellum. 5,6 The treatment of CD varies greatly and depends on the type of provider seen. Conservative management may consist of electrical stimulation or ultrasonographic therapy to the affected muscles, manual therapy or joint mobilization, manipulation, and passive/active therapeutic exercises.…”