Clinical Correlates From Periphery to Spinal Cord PDF

Clinical Correlates from periphery to spinal cord ~ Neuroscience PHT 5200 Major sites where problems can occur  Muscle (Clinical Path, ie Muscular Dystrophy)  Neuromuscular junction  Peripheral nerves  Nerve roots  Motor neuron  Spinal cord...

Clinical Correlates from periphery to spinal cord ~ Neuroscience PHT 5200 Major sites where problems can occur  Muscle (Clinical Path, ie Muscular Dystrophy)  Neuromuscular junction  Peripheral nerves  Nerve roots  Motor neuron  Spinal cord Extra-axial lesions Intra-axial lesions Tracts Trauma  select sites  entire cross-section Vascular Definitions  Motor unit: cell  Lower motor body, axon, neuron: cell body neuromuscular and axon junction, and all the http://www.baileybio.com/plogger/images/anatomy___physiology/05._powerpoint_-_muscular_system/motor_unit.jpg skeletal muscle fibers that it innervates  Diseases of chemical transmission at the NM junction Muscles can't contract  Myasthenia gravis Postsynaptic auto-immune disorder antibodies produced against nicotinic acetylcholine receptors on the muscle weakness affects cranial muscles as well as limbs manifestations vary from day to day (NOT TYPICAL of other NM diseases) dive bomber response 2 temporarily reversed by drugs that inhibit acetylcholinesterase i -keep https://www.intechopen.com/chapters/43488 "breaks down Ach in was  Diseases of chemical transmission at the NM junction  Myasthenia gravis clinical note - MSR’s typically https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRYyzzVBmjxR9-Sw085cb-DteWrY3gKI6KJddlpN-HFT-4J3MmaY7DFvMkA not affected, and nerve conduction studies are reasonably normal Why? What sensory deficits would be found? sensory deficits No be we are on & the nerve is the muscle normal Diseases of chemical transmission at the NM junction  Lambert-Eaton Presynaptic antibodies to voltage gated CA++ channels presynaptic problem https://www.youtube.com/ watch?app=desktop&v=_aT r58i5t3U Weakness repetitive stimulation builds a response from small to large (opposite of enter MG) more calcium can NMS present with some lung cancer patients and a few others https://www.intechopen.com/chapters/43488  Diseases of the peripheral nerve  Nerve injuries - Seddon’s classification system: neuropraxia  temporary block with preservation of the axon  Full recovery axonotmesis  disintegration and Wallerian degeneration of distal axon  endoneurial sheath is preserved  axon regeneration is possible neurotmesis  entire continuity of the nerve trunk is lost  Recovery is less likely What pattern of sensory loss would you https://x.com/OrthoMScUCL/status/1202654795489824769 anticipate to find on sensory evaluation? peripheral newe pattern Not dermatomal  Diseases of the peripheral nerve  Wallerian degeneration Axonotmesis PNS has limited ability to regenerate, CNS very limited atrophy of distal segment of the axon (degeneration) swelling of the proximal segment and cell body  site of protein synthesis in presence of nerve growth factor, schwann cells and macrophages two forms of regeneration itself  Regenerative same aron regrows -  Collateral nearby aton regrows aror - proceeds approx 1 mm/day https://www.nrronline.org/viewimage.asp?img=NeuralRegen Res_2015_10_12_1945_172309_f1.jpg  Factors influencing regeneration  Intactness of the cell body  Neurons do not have mitotic activity  We do not have the ability to create more neurons  Location of lesion in relation to the cell body  Closer to cell body less likely to make a functional connection  Further away from the cell body – slower the regrowth due to having to transport so far for repair and growth  Intactness of the endoneurium  Guiding the nerve regrowth  If not intact more difficult to make a functional connection  Neurotrophic factors (growth factors, growth associated proteins)  Timing of the repair – skill of the surgeon  Status of end organ at the time of reinnervation  Length of the injury zone  CNS vs PNS  CNS – much less likely to  Intrinsic theory – have regeneration ◦ That CNS neurons are  Why? intrinsically incapable of  CNS is a network not regenerating – these linear neurons cannot upregulate  Barrier theory – blocked by growth associated proteins scarring due to astrocytes (GAPs)  A contributor, but does not appear to be the entire reason ◦ All probably have a role in  Inadequacy of the blocking regeneration environment ◦ CNS myelin has proteins that inhibit growth  Diseases of the peripheral NS  Peripheral neuropathy disease of the neuron manifestations:  glove and stocking pattern due to impaired axonal transport or dying back lack of blood supply to distal newes  affects motor, sensory, and ANS neurons  Common neuropathies diabetes alcoholism Guillain-Barre syndrome Chemotherapy https://www.atsdr.cdc.gov/csem/arsenic/phy siologic_effects.html Nerve Root involvement  Compression of the spinal nerve roots  or mixed spinal nerve  Symptoms Pain Sensory loss  Dermatomal pattern Motor loss  Myotomal pattern https://sportsmedicine.mayoclinic.org/condition/radiculopathy/  Nerve Root involvement  Dermatome Area of skin, innervated by a single nerve root Dermatomes have overlap, so complete loss of a nerve root rarely results in complete loss of sensation in an area (except for CN V) due to the overlap may report decreased rather than lost sensation Fig 46-3, Kandel & Schwartz, 3rd Edition  Segmented Root Major sensory area affected C4 Clavicle C8 Fifth finger T4 Nipples T10 Umbilicus L1 Inguinal ligament L3 Anterior surface of the thigh L5 Great toe S1 Lateral aspect of the foot https://samarpanphysioclinic.com/dermatomes/  Motor neuron disorders http://neuromuscular.wustl.edu/pics/people/patients/anthornsm.jpg  Motor neuron diseases Polio ALS Amyotrophic lateral sclerosis (ALS)  Amyotrophy - Neurogenic atrophy of muscle  Lateral sclerosis - Hardness of the lateral SC on autopsy LCST lives here Astrocyte proliferation Scarring of lateral columns of SC  Pathology  Progressive degeneration UMN in cortex  Can affect corticospinal and/or corticobulbar LMN (at level of brain stem and spinal cord)  Some motor neurons are spared Those supplying ocular muscles Those involved in control of voluntary bowel and bladder sphincters ALS http://library.med.utah.edu/WebPath/jpeg5/CNS103.jpg Epidemiology  1-4/100,000  5-10% of people with the disease have a family history.  Cause is not known heavy metal intoxication has been considered Smoking Serving in the military History of brain trauma  Males>females (slightly)  Typical onset – age 40-mid 60’s Symptoms  Starts with painless weakness of extremities difficulty with fine hand movements  using tools, writing, typing  playing piano Wasting of intrinsic hand and foot muscles  Fasciculations of muscles in forearm or upper arm Symptoms  Weakness spreads rapidly  Hyperreflexia  **Sensation is always normal motor neuron problem  Does not affect autonomic motor neurons  Usually no mental deterioration. Aware of their own demise  Night muscle cramps common  Dysarthria and dysphagia (UMN-corticobulbar in origin)  Prognosis  Patient becomes increasingly dependent Usually WC dep. in 12-18 mo  “ALWAYS” FATAL Usually within 3 to 5 years Usually secondary to compromise of respiratory muscles or choking due to dysphagia End of life ethical issues  Variants of ALS  Progressive Bulbar  Spinal Muscular Palsy Atrophy First symptoms are Only lower motor restricted to muscles neurons are involved innervated by cranial weakness, wasting, nerves Fasciculation Dysarthria, dysphagia Adult SMA probably = Very rapid demise ALS Autopsy - CST involvement Role of PT  Patient/family education and support Instruct family and caregiver in maintenance stretching, transfers etc.  Adaptive devices, wheelchairs, environmental controls  Heavy strengthening is contraindicated  Did Lou Gehrig have Lou Gehrig’s Disease?  May have died from chronic traumatic encephalopathy Due to multiple concussions and other forms of head injury Identified by the presence of a tau protein (TDP-43) in spinal cord tissue (for CTE) Since Lou Gehrig was cremated, the controversy will not be conclusively resolved  Polio  Anterior horn cell/motor neuron disorder  No sensory changes  Muscle weakness  Post-polio syndrome  July 2022 – polio in US  Post-polio No heavy strengthening https://www.theguardian.com/global/2020/nov/15/the-defeat-of- polio-proved-that-immunisation-saved-lives-but-theres-a-sting-to- the-tale Disorders of the Spinal Cord  Spina Bifida  Complete transection of the cord  Anterior spinal artery syndrome  Posterior spinal artery syndrome  Brown Sequard  Central Cord  Congenital deformations of the lower spinal cord  Spina bifida  Spina bifida oculta failure to close the  Meningocele neural tube during  Myelomeningocele development Figure 5-5, Haines  Spina Bifida  Occulta http://img.tfd.com/dorland/thumbs/spina_bifida-occulta.jpg vertebrae only Meninges and cord are not impacted Usually tuft of hair over the area Incidental findings on x-ray No functional deficits  Spina bifida  Meningocele Bulging of the meninges Meningo= meninges Cele = tumor, swelling or hernia THUS – defect of the neural arch permits extension of the meninges and CSF, forming the tumor Typically repaired at birth No functional deficits since cord is not involved https://www.cdc.gov/spina-bifida/about/index.html  Spina bifida http://www.georgiahealth.edu/medicine/neurosurgery/images/myelomeningocele.jpg  Myelomeningocele Myelo – involves cord THUS – defect of the neural arch permits extension of the cord, meninges and CSF – http://body-disease.com/wp-content/uploads/2012/03/Neural-tube-defects.png May be paraplegic and loss of sensation below level Bowel and bladder problems Incidence: 5 per 100,000 Can do surgical repair in utero to minimize long term damage Complete Transection of Cord  Complete transection of the spinal cord Spinal shock – initial flaccid Later manifestations - UMN  spasticity  hyper-reflexia  present Babinski  clonus  loss of B/B If above C3, breathing is affected Incomplete is more common than complete Loss of all sensory modalities below lesion Autonomic dysreflexia increased BP due to vasoconstriction ◦ with complete lesions above T6 ◦ response is a reflex response to noxious stimuli below the level of the lesion ◦ noxious stimulus results in ANS initiating vasoconstriction ◦ body can’t compensate since normal message to vasodilate cannot pass the level of the lesion ◦ message to heart to slow thru Vagus is received https://www.researchgate.net/figure/Diagram-illustrating-how- autonomic-dysreflexia-occurs-in-a-person-with-spinal- cord_fig1_9038493  Autonomic Dysreflexia  Symptoms ◦ pounding, severe HA (due to blood pressure) ◦ Increased BP ◦ Flushing above the level of the lesion ◦ Shivering, goose pimples ◦ Bradycardia  Treatment ◦ Have patient sit ◦ Relieve the noxious stimuli https://www.researchgate.net/figure/Diagram-illustrating-how- autonomic-dysreflexia-occurs-in-a-person-with-spinal- cord_fig1_9038493 Lesion Question #1  A 27 y o male was thrown from a horse, landing on a concrete planter with the bulk of the force distributed to his back. X-rays revealed a bilateral fracture of the pars interarticularis of T12/L1, with a functional grade IV spondylolisthesis.  A. Extent of injury?  B. Type of injury (UMN or LMN)?  C. Signs and symptoms expected?  D. How would you describe the functional level?  E. What is the prognosis?  Brown-Sequard Syndrome  Hemisection of the spinal cord ipsilateral to LESION  loss of 2 pt discrimination, light touch, vibration, and proprioception  loss of voluntary motor (UMN manifestations) contralateral to LESION  loss of nocioception, temperature and crude touch may have some ipsilateral LMN involvement – only at the level of the lesion may have ipsilateral Horner’s if cervical or T1-T2  Horner’s Losing sympathetics  Sympathetic involvement  Ptosis, meiosis, anhidrosis lack of Droopy eyes pupillaryconstriction sweat  Lesion in the Getting info from hypothalamus Upper segments of the IML (T1-T2) Hypothalamus drives fibers descending to the IML from the hypothalamus in the lateral brainstem Extra axial lesion of the cervical sympathetic chain/superior cervical ganglion Anywhere in the circuit Brainster , servical , Horner’s  anhidrosis  meiosis  must be lesioned ↑ pathway to see loss below the lesion Syringomyelia  tumor on the inside of the spinal cord (formation of cysts)  typically, initial fibers affected are ALS at the crossing of the ventral white commissure – Fig 46-5, Kandel & Schwartz(Third Edition) bilateral loss of At that nociception/temp level  sensory loss can be unilateral  can also have UMN or LMN involvement, depending on the extent of the cyst https://www.mayoclinic.org/diseases-conditions/syringomyelia/symptoms-causes/syc-20354771  compression incomplete , lesion Central Cord syndrome ◦ Symptoms  UE involvement more than somatotopic due to LE involvement organization  Sensory loss and motor loss  Bladder control may be lost  Usually due to trauma or narrowing with age Medial So impacted more than lateral  intermittent daudication is differential diagnosis Spinal Stenosis SC compression  Spinal Stenosis mechanical problem due to narrowing of the spinal canal usually bilateral pain pain decreased when walking uphill forward flexion relieves pressure occurs in back, buttocks, thighs, calves, and feet normal pulses unlike intermittent daudication - peaks in 7th decade, affects men more than women Anterior Spinal Artery Syndrome  Anterior Spinal Artery supplies the anterior 2/3rds of the spinal cord medullary arteries reinforce the ASA  artery of Adamkiewicz (most common at L2) Signs and Symptoms? UMN problem be tracts are impacted LMN problem at that level Posterior Spinal Artery Syndrome  Deficits? DCML same side below Cauda equina syndrome Below vertebral level L2 Symptoms  Saddle sensory loss  LMN loss  Bowel and Bladder difficulties  Pain – low back and radiating  LMN problem be there's no cord spinal. Dermational sensory loss Fig 46-2a, Kandel & Schwartz (Third Edition) Spinal cord syndromes https://clinicalgate.com/paraplegia-and-spinal-cord-syndromes/  Systemic Problems that affect the spinal cord  Subacute combined  Tabes Dorsalis - degeneration of the SC ◦ Syphilitic myelopathy ◦ Pernicious anemia, vitamin ◦ Locomotor ataxia B12 deficiency in alcoholics - seen ◦ Demyelination of the dorsal ◦ Patchy losses of myelin in columns the dorsal column and ↳ DCML ◦ Loss of DCML modalities lateral column ◦ Sensory ataxia, ↳ Lost ◦ Also can have peripheral ◦ incoordination, wide based, neuropathy high steppage gait with foot ◦ Symptoms: proprioceptive slap loss, numbness, spastic ◦ Loss of reflexes paresis, urinary ◦ *Sir Arthur Conan Doyle completed his dissertation on Tabes Dorsalis in 1885 incontinence, clumsy gait, incoordination https://www.youtube.com/watch?v=-rRNdGJ3LxI Friedreich’s Ataxia genetic condition tracts involved:  *DSCT unconscious proprioception -  LCST motor to limbs -  DCML conscious proprioception - ataxia uncoordinated - spastic paralysis in legs loss of proprioception loss of motor - reflexes present Babinski BUT, loss of KJ and AJ (may be due to cerebellar involvement) https://www.youtube.com/watch?v=JampkXmVEg4 Questions?