Brain regions, lesions, and stroke syndromes
Christos Tziotzios, Jesse Dawson, Matthew Walters, Kennedy R Lees in Stroke in Practice, 2017
The last (but not the least important) part of the hindbrain is the cerebellum, which sits comfortably in the posterior cranial fossa. The cerebellum is formed by the two hemispheres joined by the worm-like structure known as cerebellar vermis. The cerebellum also consists of an outer layer of grey matter (cerebellar cortex) and inner white matter. Within the deeper white matter are four pairs of nuclei that interconnect with the cerebellar cortex and with certain cell body aggregates of the brainstem and thalamus. From a functional standpoint, the cerebellum is responsible for the maintenance of equilibrium and posture and skeletal muscle tone as well as coordination of movement, all at a subconscious level. A stroke in the cerebellum will cause a lack of coordination in upper and lower limbs manifesting as hypotonia or intention tremor, dysdiadochokinesis, and an ataxic, wide-based gait. When the lesion is unilateral, the deficit is likewise. When the median cerebellar vermis is involved, a vertiginous labyrinthine syndrome may result that closely mimics a peripheral vestibulopathy. A cerebellar stroke can also impair eye movement by affecting the coordinated function of extraocular musculature, thereby leading to nystagmus with the fast component pointing toward the side of the lesion. Dysarthria may ensue but is not sign specific to stroke, as it is commonly seen with bilateral cerebellar involvement, as in alcohol intoxication, hypothyroidism, and multiple sclerosis.
The Problems
John Greene, Ian Bone in Understanding Neurology a problem-orientated approach, 2007
Anatomically, the cerebellum occupies most of the posterior cranial fossa. It has an outer mantle of grey matter (cerebellar cortex), internal white matter, and a set of deep nuclei. There are two cerebellar hemispheres connected by a midline strip termed the cerebellar vermis. The part of the hemisphere closest to the vermis is called the intermediate region and the rest of the hemisphere comprises the lateral region. The cerebellum receives input from all levels of the central nervous system, mostly by way of two pairs of large fibre tracts known as inferior and middle cerebellar peduncles. The paired superior cerebellar peduncles comprise the major cerebellar outflow tracts to the motor regions of the cerebral cortex and brainstem. These fibres originate in the deep cerebellar and vestibular nuclei before relaying through the Purkinje cells.
Intracranial Cysts
Amar Bhide, Asma Khalil, Aris T Papageorghiou, Susana Pereira, Shanthi Sairam, Basky Thilaganathan in Problem-Based Obstetric Ultrasound, 2019
Cystic structures in the posterior fossa include: Enlarged cisterna magna when it is >10 mm in the transverse cerebellar view. Detailed ultrasound is needed to demonstrate this is isolated and that the cerebellum and vermis are normal. It can be associated with ventriculomegaly, but if it remains isolated and does not progress, prognosis is generally good.Blake's pouch cysts represent a communication between the 4th ventricle into the cisterna magna and appear as a unilocular cyst without any Doppler flow. Careful assessment is mandatory to ensure the remainder of the brain—in particular cerebellum and vermis—are normal. This is usually isolated, and most will resolve spontaneously.In Dandy-Walker malformation there is dilation of the fourth ventricle in the posterior fossa and that extends into the cisterna magna. The cerebellar vermis will be hypoplastic or absent. The condition is often associated with chromosomal abnormalities (mainly trisomy 18 and 13) or genetic syndromes. Coexisting abnormalities are very common, as is severe ventriculomegaly. The outlook is guarded.
Neuropsychiatric systemic lupus erythematosus with cerebellar vasculitis and obstructive hydrocephalus requiring decompressive craniectomy
Published in Modern Rheumatology Case Reports, 2021
Nobuhito Naito, Hiroshi Kawano, Yuya Yamashita, Mayo Kondo, Shotaro Haji, Ryosuke Miyamoto, Yuko Toyoda, Yasuhisa Kanematsu, Yuishin Izumi, Yoshimi Bando, Yasuhiko Nishioka
However, on the second day of mPSL pulse therapy, consciousness disorder (Glasgow Coma Scale [GCS] E3V4M6) appeared suddenly, and brain computed tomography (CT) revealed cerebellar oedema with obstructive hydrocephalus caused by cerebellar oedema (Figure 3). Emergency decompressive craniectomy was performed in order to save her life. At the time of surgery, a biopsy of the cerebellar vermis was also performed. Histological examinations of the biopsy specimens showed infiltration of inflammatory cells around some blood vessels with fibrinoid necrosis, findings that were compatible with features of vasculitis (Figure 4). Given these histological findings, she was treated with additional intermittent pulse intravenous cyclophosphamide (IVCY) therapy (500 mg/m2) every 4 weeks. After surgery, her headache and consciousness disorder improved (Figure 5). The regression of the high-intensity area along the sulci of the bilateral cerebellar hemispheres was observed on MRI after the second dose of IVCY (Figure 2(C)).
Current perspectives on galvanic vestibular stimulation in the treatment of Parkinson’s disease
Published in Expert Review of Neurotherapeutics, 2021
Soojin Lee, Aiping Liu, Martin J. McKeown
Postural instability is one of the main disabling symptoms largely refractory to L-dopa in PD. The cerebellum plays a critical role in postural control and gait through its close connection with the vestibular system. The vestibulocerebellum (the flocculonodular lobe and adjacent parts of the caudal cerebellar vermis) receives a substantial amount of its input from the vestibular nuclei and is involved in the regulation of posture and equilibrium as well as the vestibulo-ocular reflex – a reflex to generate eye movements for stabilization of retinal images during head movements [72]. Thus, GVS could subserve some of the vestibulocerebellar functions altered in PD through this pathway. Notably, the postural instability in PD is closely associated with dysfunction of vestibular processing [71] and can be improved by vestibular rehabilitation [73].
Ataxia-telangiectasia: epidemiology, pathogenesis, clinical phenotype, diagnosis, prognosis and management
Published in Expert Review of Clinical Immunology, 2020
Parisa Amirifar, Mohammad Reza Ranjouri, Martin Lavin, Hassan Abolhassani, Reza Yazdani, Asghar Aghamohammadi
Progressive cerebellar degenerations in A-T patients originate from atrophy of the cerebellar vermis and hemispheres, resulting from a negative impact on the Purkinje cells, granule neurons, and basket cells [52]. Magnetic resonance imaging (MRI) is the preferred method for evaluation of the central nervous system (CNS) and spinal cord degeneration in A-T patients. MRI studies may document the progressive cerebellar atrophy [52,56]. It has been estimated that almost 95% of A-T patients present cerebellar atrophy at any time in the disease course. In fact, cerebellar ataxia is the most common pediatric presentation of A-T patients [57]. Intellectual disability and microcephaly are not commonly observed in A-T patients. However, they occasionally manifest [58]. Loss of tendon reflexes (particularly distal to proximal advancing) is another feature occurring in some A-T patients, reflecting a progressive sensory and motor neuropathy [59]. For the majority of A-T patients, MRI is normal in the toddler years and early childhood years. In elder patients, degeneration of the cerebellar vermis and hemispheres is mostly observed [60]. Verhagen et al. proposed that cerebellar atrophy was likely to be found in elderly patients with classic A-T but rarely in patients with mild A-T [61].
Related Knowledge Centers
- Cerebellar Hemisphere
- Cerebellum
- Posterior Cranial Fossa
- Skull
- Spinal Cord
- Primary Fissure of Cerebellum
- Lobe
- Spinal Posture
- Head
- Prenatal Development