Clinical diagnosis
Case 116
【Progress】Both patients got rehabilitation for three months which induced improvement of motor dysfunction of the disable sided extremities. They were discharged and continued exercise at home according to our rehabilitation program.
【Discussion】
It is undoubtful that cerebellum is a neural center of coordinating motion : preservation of equilibrium and accommodation of muscle tonus. Cerebellum is formed by three parts from a point of functional view: flocculus and nodulus (part of vermis), vermis and cerebellar hemisphere. Each part has a specific function; flocculus and nodulus functions equilibrium accompanied with vestibular nucleus connected to three semicircular canals of the ear; Vermis functions rising against earth gravitation by constriction and relaxation of muscles: cerebellar hemisphere functions walking with two legs.
Cerebellum has three peduncles: superior cerebellar peduncle connects to middle brain; middle cerebellar peduncle connects to pons: inferior cerebellar peduncle connects to medullary oblongata. Major neuron of superior cerebellar peduncle includes two efferent (outflow) neural tracts from Purkinje cells to cerebral cortex via dental nucleus and thalamus, and from Purkinje cells to nucleus ruber (red nucleus) in the midbrain. As minor neuron, superior cerebellar peduncle has afferent neural tract of anterior (ventral) spinocerebellar tract from below L3 to vermis. Middle cerebellar tract include afferent neural tract from cerebral cortex to granular layer and Purkinje cells. Major neuron of Inferior cerebellar peduncle include four afferent (inflow) neural tracts; From vestibular nucleus to flocculus and nodulus; From posterior (dorsal) spinocerebellar tract from Th1 to L3 to vermis; From cervical spinal cord (C1 to C7) neuron to vermis; From olive nucleus to Purkinje cells (olive-cerebellar tract). As minor efferent neural tract, inferior cerebellar peduncle has neural route from flocculus and nodulus via nucleus fastigii to vestibula nucleus.
As described above, there are three major neuron reflex circuits; Cerebral circuit, cerebral cortex - pontine nucleus - middle cerebellar peduncle - granular layer and Purkinje cells – dental nucleus - superior cerebellar peduncle – thalamus - cerebral cortex; Vestibular circuit, three semicircular canals – vestibular nerve – vestibular nucleus – inferior cerebellar peduncle – flocculus and nodulus – nucleus fastigii – inferior cerebellar peduncle – vestibular nucleus; Red nucleus Olive circuit, red nucleus – tegmental central tract – olive nucleus -inferior cerebellar peduncle – Purkinje cells – superior cerebellar peduncle – red nucleus. Further, although it is not the complete circuit, another connection is imperative to get acquainted with the route about information of muscle spindle and tendon organ of Golgi which are in charges of muscle strain and relaxation, respectively, entering into cerebellum. Namely, the information from cervical spine and Th1 to L3 enters to vermis via inferior cerebellar peduncle and the information from below L3 enters vermis via superior cerebellar peduncle. Neural information emerging from vermis to red nucleus (spine) or to thalamus (cerebral cortex), indicating all information from cerebrum and spinal cord are shared with cerebellum. Despite these connections, the activity of cerebellum is performed unconsciousnessly.
Brain MRI showed hemi-lateral infarction of middle cerebral peduncle due to ischemia of anterior inferior cerebellar artery, causing the same-sided cerebellar disorder.
【Summary】
We present two cases with infarction of middle cerebellar peduncle showed by MRI with diffusion weighted imaging. They suffered from ipsi-lateral ataxia such as chopstick using, writing and walking. We should keep in mind that cerebellum is a center of motion co-ordination which is in charge of equilibrium, rising against earth gravitation and standing and walking with two legs. Vestibular circuit (flocculus and nodulus – vestibular nucleus via inferior cerebellar peduncle) is related to equilibrium. Cerebral circuit (cerebral cortex, pontine – granular layers and Purkinje cells - middle cerebellar peduncle – dental nucleus – superior cerebellar peduncle - thalamus) is related to walking with upper and lower extremities. Red nucleus Olive circuit (afferent route via inferior cerebellar peduncle – vermis - efferent route via superior cerebellar peduncle) and connection of spine to cerebellum (afferent route of cervical spine axon and Th1-L3 axon via inferior cerebellar peduncle, below L3 axon via superior cerebellar peduncle, - vermis - efferent route via superior cerebellar peduncle – red nucleus) is related to standing up against earth gravitation.
【References】
This article is written based on the documents of the book below
Peter Duus. Neuroloigisch-topische Diagnostik: Anatomie Physiologie Klinik, second edition translated in Japanese by Hajime Handa and Junya Hanakita. Bunkodo, Tokyo
2018.8.8