CN V! touch! pain! Touch! P/T!
Visual Pathways! L! R! B! A! C! D! LT! E! F! RT! G!
hypothalamospinal! and! ALS!
Vestibular Pathways! 1. Posture/Balance!!falling! 2. Head Position! 3. Eye-Head Movements nystagmus!!(vestibulo-ocular reflex)! 4. Autonomic Cnt!nausea/vomiting! 5. Perception!!vertigo! MLF! LVST! MVST!
Auditory Pathways! of thalamus!
FUNCTION! COMPONENT! DEFICITS! Start! Basal Ganglia! Spontaneous Movements! Move! UMN/LMN! Cerebral Cortex! Brainstem, Spinal cord! Roots/peripheral nerves! Plan! Cerebellum! Ataxia! Adjust! Cerebellum! Ataxia! Weak/Paralyzed! Balance/EyeMove! Cerebellum! Loss of balance! Nystagmus!
UMN/LMN!
Thalamus! Cerebral Cortex! Basal Ganglia! Function: ideation, planning, execution! Cerebellum! 3! head muscles! body muscles! Brainstem! 2! Spinal Cord! 1! Function: cause muscle contraction!
Paresis Flaccid, ipsilateral to injury! Decreased tendon reflexes! Decreased muscle tone! Severe muscle atrophy! Fasciculations twitching muscle fibers due to abnormal transmitter release at neuromuscular junction!
For Body:!! Corticospinal tract!! Cortico-Bulbo-spinal tracts! Thalamus! Cerebral Cortex! Basal Ganglia! Cerebellum! head muscles! Brainstem! Body muscles! Spinal Cord!
Lateral Corticospinal T controls limb motoneurons especially for fine movements of hands and feet.! Ventral Corticospinal T (10%) crosses later in spinal cord to influence axial motoneurons, but significance unknown.! Lateral CST! 90%!
Post limb of internal capsule! Crus cerebri of midbrain! Basilar pons! Pyramids of medulla! Lateral corticospinal tract!
Lateral Corticospinal T provides commands for limb motoneurons - especially for fine movements of hands and feet.! Bulbospinal tracts are controlled by motor cortical areas and cerebellum. They influence posture and muscle tone.!
Reticulospinal T! Vestibulospinal T! Rubrospinal T! Ex!t!en!s!or!moton!e!uron!s! o!f! upp!e!r/lo!we!r!limb!s! U!pp!e!r!l!imb!f!lexo!r! moton!e!uron!s!
1. Paresis/paralysis! 2. Increased muscle tone- Spasticity! 3. Increased tendon reflexes! 4. Babinski sign a reflex induced by stroking the plantar surface of the foot!
Controlled by 2 component system also! UMN- corticobulbar fibers! LMN- motor cranial nerves! Thalamus! Cerebral Cortex! Basal Ganglia! Cranial nerves! head muscles! Cerebellum! Brainstem! Corticobulbar T! Spinal Cord!
Cranial Nerve Motoneurons:! midbrain!! CN III, IV extrinsic eye muscles! pons! medulla!! CN V jaw muscles!! CN VI!! CN VII facial muscles!! CN IX, X = Nucleus Ambiguus!for larynx, pharynx!! CN XII tongue! midbrain! pons! medulla!! CN XI trapezius, sternocleidomastoid!
Cranial Nerve Lesions ipsilateral effects on muscles!! CN III, IV, VI!paralysis of extrinsic eye muscles!! CN V!jaw deviates to paralyzed side!! CN VII!paralysis of facial muscles!! Nuc Ambiguus!loss of gag reflex/swallowing, hoarseness,!!!uvula deviates to opposite side!! CN XII!tongue deviates to paralyzed side!! CN XI!weakness in shoulder shrug, head turn to!!!!!opposite side! Midline structures often deviate to one side when muscles are weak/paralyzed on one side.!
CST! Most corticobulbar fibers synapse on cranial nerve motor nuclei bilaterally.! V! VII! XII! Nuc ambiguus! travel together!
1. CN VII - lower facial muscles! 2. CN XII - tongue!
Lesions of corticobulbars on one side cause weakness or paralysis of the lower face on the opposite side.! For Lesion on RT! R! L! VII! lower face! working! not working!
Corticobulbar fibers supply Hypoglossal Nuc is stronger contralaterally.! RT corticobulbar lesion causes tongue to deviate to opposite side.! R! L! CN XII!
Basal Ganglia!
Thalamus! Cerebral Cortex! Basal Ganglia! Cerebellum! head muscles! Brainstem! body muscles! Spinal Cord!
1. Caudate! } 2. Putamen! Striatum! 3. Globus Pallidus! 4. Substantia Nigra! 5. Subthalamic Nucleus!
Output of Basal Ganglia! SN c! VL! dopamine! STN!
Physiological Basis of Function/Disease! Cortex motor areas! Putamen! SNc! D2! D1! SNc! GPe! STN! GPi! VL!
Symptoms of BG Diseases! Dyskinesias movement disorders!! hemiballismus!!!!! chorea!! dystonia/athetosis!! resting tremor! Hypokinesia / Bradykinesia! Rigidity lead pipe with cogwheeling! Changes in posture!
Disease! Lesion Site! Symptoms! Ballism! STN! Wild,flailing movements! Parkinson s! SNc! Resting tremor, movement, rigidity, altered gait/posture! Huntington s! Tardive dyskinesia! Caudate/Putamen! Chorea, dementia! Dopamine and other Receptors! Facial chorea/athetosis! Tourettes s! unknown! Motor and verbal tics! Wilson s Disease, CO poisoning!
Cerebellum!
1. Controls 3 functions: plan, adjust, balance/eye mov! 2. The 3 functions = 3 regions of cerebellum! 3. How it works: regulates UMNs (cortex and brainstem)! 4. Damage to cerebellum/pathways ataxia (+ vestib symp)!
Vestibulocerebellum! nodulus and flocculus! Spinocerebellum! Vermis / Hemisphere! Cerebrocerebellum! Hemisphere!
vestibulocerebellum! Lesions - Vestibular symptoms!! - falling, wide-based gait,!!!!nystagmus, nausea, vertigo! nodulus/flocculus!
Midline symptoms! Limb symptoms!
Flocculus/Nodulus! Vestibular Signs! Vermis! Truncal Ataxia! Cerebellar Hemisphere! There are 2 categories of cerebellar symptoms! Limb Ataxia! 1. Vestibular Ataxic Gait! Signs! Falling! Ataxic Gait! Nystagmus!! Nausea,! vertigo!!!2. Ataxia! intention tremor, dysmetria, asynergia, etc! 4th ventricle tumors! Alcohol, MS, tumor! Tumor, infarct, MS!
1. Cerebellar symptoms are caused by damage to cerebellum, its peduncles or pathways.! 2. Cerebellar damage produces motor deficits on same side of body.! 3. Cerebellar signs fall into 2 categories:!!! Vestibular - falling/ataxic gait, nystagmus!!! Ataxia!!!! trunk - vermis!!!! limbs - hemisphere, peduncles, pathways!
Ataxia/Asynergia/! Decomposition of Movement! Dysmetria! Lack of Check! Inappropriate force! Dysdiadochokinesia! Intention/kinetic tremor! Hypotonia! limbs! Dysarthria!