The cerebellum, located under the posterior cerebral cortex in the posterior cranial fossa, just posterior to the brainstem, has diverse connections to the brain stem, cerebrum, and spinal cord.[1]
Embryologically it develops from hindbrain or rhombencephalon. The cerebellum subdivides into two hemispheres connected by the vermis, a central midline part.Any midline cerebellar lesions manifest as imbalance, while hemispheric cerebellar lesions result mainly in incoordination.[2]
The cerebellum maintains our motor equilibrium and calibration of movements. It is an essential region of the brain playing a central role in maintaining our gait, stance, and balance, as well as the coordination of goal-directed movements and complex movements. Dysfunction manifests as clumsiness and "drunken" gait.
The cerebellum contains a considerable number of neurons in a limited volume, possibly due to the folding of the cortex of the cerebellum, and the neurons are mainly present close to periphery.
Cerebellar dysfunction causes balance problems and gait disorders along with difficulties in coordination resulting in ataxia, uncoordinated movements, imbalance, speech problems(dysarthria), visual problems (nystagmus) and vertigo as a part of the vestibulocerebellar system. There are several reasons for these defects. Some are vascular (due to stroke, hemorrhage), idiopathic, iatrogenic, traumatic, autoimmune, metabolic, infectious, inflammatory, neoplastic, and some rare genetic disorders. An etiological evaluation is necessary for the diagnosis of cerebellar dysfunction and the treatment of cerebellar disorders.
Cerebellar dysfunction results from a heterogeneous group of disorders and can occur in isolation or as part of a range of neurological or systemic features. There are several reasons for these defects. These can be vascular (due to stroke, hemorrhage), idiopathic, iatrogenic (drug), traumatic, autoimmune, metabolic, infective, inflammatory, neoplastic, toxic, and rare genetic disorders. We can divide this according to the involvement of one or both sides.
A. Bilateral cerebellar dysfunctions (most important causes are):
B. Unilateral cerebellar dysfunctions (most important causes are):
C. Spastic paraparesis with cerebellar signs (the most important causes are):
This factor strongly varies according to etiologies. Stroke is more common after 45 years, and genetic causes are typically diagnosed during childhood. Research has not revealed any differences in incidence or prevalence between males and females in primary diseases, but according to etiology, it can vary. Men have demonstrated more neurological gait problems compared to women.[5]
Cerebellar syndrome results from a heterogeneous group of disorders and can occur in systemic features or isolation or as part of a range of neurological presentations. The patient will often undergo a cerebellar examination by instructions referring to coordination, imbalance, or difficulty performing smooth movements and goal-directed tasks. There are several reasons for these defects, as discussed here.[6]
Cerebellar examinations are mandatory to diagnose exact etiologies.An important part of cerebellar examinations:[7][8][2][9]
A simple mnemonic to remember some of the cerebellar signs is DANISH:
Following Examinations are required to find out and correlate the etiology:
Investigations to find out most likely cause:[12][13]
Treatment of cerebellar dysfunction initially involves diagnosing the underlying causes. A proper diagnosis leads to more accurate treatment plans.
These plans can require a multidisciplinary approach incorporating, physiotherapy, occupational therapy, and medications. The treatment plans range in complexity based on the severity of symptoms and etiology.Patients with vitamin deficiency can be educated and prescribed proper supplementation to increase their body’s levels. Following up with routine laboratory work is essential in these patients to ensure the achievement of therapeutic levels of vitamins.[10]Patients can benefit from rehabilitation, gait training, use of gait assistive devices, and fall preventive measures. Commonly used exercise interventions such as coordination training, muscle strength, power, as well as resistance training, can improve routine and maximum gait and balance problems in the elderly.
The suspicion of gait disturbances demands a broad differential encompassing numerous etiologies. The following potential causes should be ruled out to come up with a final diagnosis.Other form of Ataxias: Vestibular and sensory ataxia[15]
Neurologic: Parkinson, dementia, stroke, subacute combined degeneration, amyotrophic lateral sclerosis
Metabolic: Diabetes mellitus, encephalopathy, obesity, vitamin B12 deficiency, uremia
The prognosis of cerebellar disturbances depends on the etiology. Metabolic and nutritional etiologies of cerebellar dysfunction have a relatively good prognosis. Some neurologic diseases must be treated symptomatically only, and often worsen over time.
The risks of having cerebellar dysfunction should be explained to the patient, so they become aware. These risks include:
Patient education and counseling, according to the patient's need, and formation of a multidisciplinary team for better management and patient outcomes.
Patient education is a vital part of identifying cerebellar dysfunctions; early detection can lead to better outcomes and prevent complications. Corrective surgery, genetic counseling, rehabilitation, gait training, use of supportive devices, and fall prevention measures require implementation.
There are several reasons behind cerebellar dysfunction. An etiological evaluation is necessary for the diagnosis of cerebellar dysfunction and treatment. Cerebellar dysfunction has a tremendous impact on patients, especially on the quality of life, gait and balance problems, morbidity, and mortality. The role of rehabilitative strategies is critical for most underlying etiologies. A collaborative multidisciplinary approach can provide comprehensive patient care, enhance team performance, and ultimately improve patient outcomes.
[1] | Roostaei T,Nazeri A,Sahraian MA,Minagar A, The human cerebellum: a review of physiologic neuroanatomy. Neurologic clinics. 2014 Nov; [PubMed PMID: 25439284] |
[2] | Jimsheleishvili S,Dididze M, Neuroanatomy, Cerebellum 2020 Jan; [PubMed PMID: 30844194] |
[3] | Kular S,Cascella M, Chiari I Malformation . 2020 Jan [PubMed PMID: 32119496] |
[4] | Shen J,Shen J,Huang K,Wu Y,Pan J,Zhan R, Syringobulbia in Patients with Chiari Malformation Type I: A Systematic Review. BioMed research international. 2019 [PubMed PMID: 31016190] |
[5] | Verghese J,LeValley A,Hall CB,Katz MJ,Ambrose AF,Lipton RB, Epidemiology of gait disorders in community-residing older adults. Journal of the American Geriatrics Society. 2006 Feb; [PubMed PMID: 16460376] |
[6] | Mitoma H,Buffo A,Gelfo F,Guell X,Fucà E,Kakei S,Lee J,Manto M,Petrosini L,Shaikh AG,Schmahmann JD, Consensus Paper. Cerebellar Reserve: From Cerebellar Physiology to Cerebellar Disorders. Cerebellum (London, England). 2020 Feb; [PubMed PMID: 31879843] |
[7] | Gudlavalleti A,Tenny S, Cerebellar Neurological Signs 2020 Jan; [PubMed PMID: 32310540] |
[8] | Thaller M,Hughes T, Inter-rater agreement of observable and elicitable neurological signs. Clinical medicine (London, England). 2014 Jun; [PubMed PMID: 24889570] |
[9] | Severino M,Huisman TAGM, Posterior Fossa Malformations. Neuroimaging clinics of North America. 2019 Aug; [PubMed PMID: 31256860] |
[10] | Sun W,Li G,Lai Z,Lu Z,Lin Y,Peng J,Huang J,Hu K, Subacute Combined Degeneration of the Spinal Cord and Hydrocephalus Associated with Vitamin B12 Deficiency. World neurosurgery. 2019 Aug; [PubMed PMID: 31082549] |
[11] | Ramaekers VT,Heimann G,Reul J,Thron A,Jaeken J, Genetic disorders and cerebellar structural abnormalities in childhood. Brain : a journal of neurology. 1997 Oct; [PubMed PMID: 9365367] |
[12] | D'Arrigo S,Viganò L,Grazia Bruzzone M,Marzaroli M,Nikas I,Riva D,Pantaleoni C, Diagnostic approach to cerebellar disease in children. Journal of child neurology. 2005 Nov; [PubMed PMID: 16417854] |
[13] | Patel S,Barkovich AJ, Analysis and classification of cerebellar malformations. AJNR. American journal of neuroradiology. 2002 Aug; [PubMed PMID: 12169461] |
[14] | Valente EM,Nuovo S,Doherty D, Genetics of cerebellar disorders. Handbook of clinical neurology. 2018; [PubMed PMID: 29903444] |
[15] | Ashizawa T,Xia G, Ataxia. Continuum (Minneapolis, Minn.). 2016 Aug; [PubMed PMID: 27495205] |