Structural changes of cerebellum and brainstem in migraine without aura.

BACKGROUND: Increasing evidence has suggested that the cerebellum is associated with pain and migraine. In addition, the descending pain system of the brainstem is the major site of trigeminal pain processing and modulation and has been discussed as a main player in the pathophysiology of migraine. Cerebellar and brainstem structural changes associated with migraineurs remain to be further investigated. METHODS: Voxel-based morphometry (VBM) (50 controls, 50 migraineurs without aura (MWoAs)) and diffusion tensor imaging (DTI) (46 controls, 46 MWoAs) were used to assess cerebellum and brainstem anatomical alterations associated with MWoAs. We utilized a spatially unbiased infratentorial template toolbox (SUIT) to perform cerebellum and brainstem optimized VBM and DTI analysis. We extracted the average diffusion values from a probabilistic cerebellar white matter atlas to investigate whether MWoAs exhibited microstructure alterations in the cerebellar peduncle tracts. RESULTS: MWoAs showed decreased fractional anisotropy (FA) in the vermis VI extending to the bilateral lobules V and VI of the cerebellum. We also found higher axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) in the right inferior cerebellum peduncle tract in MWoAs. MWoAs exhibited both reduced gray matter volume and increased AD, MD and RD in the spinal trigeminal nucleus (SpV). CONCLUSION: MWoAs exhibited microstructural changes in the cerebellum and the local brainstem. These structural differences might contribute to dysfunction of the transmission and modulation of noxious information, trigeminal nociception, and conduction and integration of multimodal information in MWoAs. These findings further suggest involvement of the cerebellum and the brainstem in the pathology of migraine without aura.

Ramsay Hunt syndrome associated with solitary nucleus, spinal trigeminal nucleus and tract, and vestibular nucleus involvement on sequential magnetic resonance imaging.

Ramsay Hunt syndrome (RHS) is an acute peripheral facial nerve paralysis typically accompanied by erythematous vesicular lesions of the auricular skin. The etiology is considered to be geniculate ganglionitis due to reactivation of varicella-zoster virus (VZV). Encephalitis is a rare but serious complication of VZV reactivation. Clarifying the regional and temporal evolution of the lesions on magnetic resonance imaging (MRI) would help with understanding the pathology of the lesion, but this information is lacking in encephalitis with RHS. Therefore, here, we reviewed sequential MR images in three RHS cases complicated by brainstem lesions. All the regions of the lesions represent specific neuronal structures-the ipsilateral solitary nucleus (SN) and spinal trigeminal nucleus and tract (STNT) in case 1; bilateral SN, ipsilateral STNT, and vestibular nucleus in case 2; ipsilateral SN and vestibular nucleus in case 3-and this seems to account for the persistent robust symptoms. Case 1 initially showed no abnormalities on MRI and cases 2 and 3 showed weak signals on the first MRI which subsequently plateaued. These observations suggest the timeframe within which it becomes possible to detect regional and temporal evolution, namely, that the distribution of the affected regions expands between weeks 2 and 5 after onset of facial paralysis. These observations and the findings of a literature review indicate that the SN, STNT, and vestibular nucleus are relatively prone to developing encephalitis after RHS.

The migraine generator revisited: continuous scanning of the migraine cycle over 30 days and three spontaneous attacks.

Functional imaging using positron emission tomography and later functional magnetic resonance imaging revealed a particular brainstem area that is believed to be specifically activated in migraine during, but not outside of the attack, and consequently has been coined the 'migraine generator'. However, the pathophysiological concept behind this term is not undisputed and typical migraine premonitory symptoms such as fatigue and yawning, but also a typical association of attacks to circadian and menstrual cycles, all make the hypothalamus a possible regulating region of migraine attacks. Neuroimaging studies investigating native human migraine attacks however are scarce and for methodological but also clinical reasons there are currently no studies investigating the last 24 h before headache onset. Here we report a migraine patient who had magnetic resonance imaging every day for 30 days, always in the morning, to cover, using functional imaging, a whole month and three complete, untreated migraine attacks. We found that hypothalamic activity as a response to trigeminal nociceptive stimulation is altered during the 24 h prior to pain onset, i.e. increases towards the next migraine attack. More importantly, the hypothalamus shows altered functional coupling with the spinal trigeminal nuclei and the region of the migraine generator, i.e. the dorsal rostral pons during the preictal day and the pain phase of native human migraine attacks. These data suggest that although the brainstem is highly linked to the migraine biology, the real driver of attacks might be the functional changes in hypothalamo-brainstem connectivity.

[Trigeminal Herpes Zoster Presenting with High-intensity Signals for the Spinal Trigeminal Nucleus and Tract on Diffusion-weighted Image: A Case Report of Stroke Mimic].

A 50-year-old woman was admitted to our hospital with dysesthesia on the right upper portion of her face and a headache. Diffusion-weighted brain magnetic resonance imaging (MRI) revealed high-intensity signals in the dorsolateral portion of the medulla oblongata. She was diagnosed with lateral medullary infarction and was intravenously treated with sodium ozagrel. On the second day of hospitalization, she had nausea and vomiting and showed nystagmus to all directions, suggesting damage to the vestibular nucleus. These manifestations coincided with partial symptoms of lateral medullary syndrome. On the third day of hospitalization, a rash appeared on the region of skin innervated by the first and second branches of the right trigeminal nerve. A reevaluation of the MRI findings indicated the presence of a lesion of the right spinal trigeminal nucleus and tract. She was treated with acyclovir for 14 days, and was discharged without any residual symptoms. Varicella zoster virus-DNA was detected in her cerebrospinal fluid. This disease mimics the presentation of a stroke and is important for differential diagnosis. (Received August 1, 2017; Accepted September 14, 2017; Published February 1, 2018).

Computed tomography-guided trigeminal tractotomy-nucleotomy in the management of vagoglossopharyngeal and geniculate neuralgias.

OBJECTIVE: Vagoglossopharyngeal and geniculate neuralgias are less frequently seen types of cranial neuralgias. Their causes and symptomatology are similar to those of trigeminal neuralgia; however, the complex anatomic relationship between the intermedius, vagal, and glossopharyngeal nerves leads to difficulties in the diagnosis and management of neuralgias originating from these cranial nerves. Numerous procedures have been used to treat intractable neuralgias of the VIIth, IXth, and Xth cranial nerves: 1) extracranial sectioning of the cranial nerves, 2) percutaneous thermal rhizotomy, 3) intracranial glossopharyngeal and vagal rhizotomies, 4) microvascular decompression, and 5) percutaneous trigeminal tractotomy-nucleotomy (TR-NC) or nucleus caudalis dorsal root entry zone operation. We propose that computer-guided TR-NC may be the first-choice operation for patients with glossopharyngeal, vagal, or geniculate neuralgia. PATIENTS AND METHODS: Nine patients suffering from idiopathic vagoglossopharyngeal neuralgia (six patients) and geniculate neuralgia (three patients) were managed at our clinic. Computed tomography-guided percutaneous trigeminal TR-NC was performed for these nine patients. RESULTS: Excellent (six patients) or good (three patients) pain control was obtained in each patient. Complications included temporary ataxia in two patients after TR-NC. CONCLUSION: The risk:benefit ratio should be evaluated individually to select the appropriate treatment procedure for patients with vagoglossopharyngeal and geniculate neuralgias. Computed tomography-guided percutaneous TR-NC is an effective and minimally invasive procedure for such patients.