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Home , Brain damage, Cauda equina syndrome, Nerve injury

Overview of Neurological Conditions

Dr. David Lipson, MD FRCPC, Physical Medicine and Rehabilitation Purpose

Overview of pertinent neurological conditions Build basic understanding of Diagnosis Presentation/manifestations Investigations Complications Issues on causation Management Basic understanding of associated functional limitations Agenda

Acquired Peripheral injury and peripheral neuropathy Specific neuro conditions , MS, GBS, CRPS, etc… Not covering cognitive as this is Dr. Zakzanis’ talk

Catch all term that incorporates all non-congenital/non-developmental , including traumatic brain injury Brain damage in the first year or two of life is often categorized separately and will usually fall under Includes Anoxic brain injury Traumatic Brain Injury Brain injury from metabolic disturbances Brain damage from Brain damage from intoxication All forms of brain injury Acquired Brain Injury cont…

In medical legal world usually most interested in traumatic brain injury Talk will focus more so on traumatic brain injury Important to note that other causes of acquired brain injury may coexist with traumatic brain injury and may be part of secondary injury cascade Traumatic brain injury

Injury to the brain from an externally applied force Usually graded in severity on the basis of loss of consciousness (and duration), post-traumatic (duration), and GCS score 30-60 minutes post injury May or may not involve structural damage to the brain tissue Trauamtic brain injury severity Mild TBI

Deficits associated with mild TBI may or may not be permanent Mild TBI may or may not be associated with identifiable structural damage on conventional neuroimaging Concussion is a subset of mild TBI Concussion

A subset of mild TBI Functional, not structural disturbance in brain function Caused by trauma to the head, or trauma to the body with impulsive force transmitted to the head Standard neuroimaging is typically normal If traumatic abnormalities seen on conventional neuroimaging or if parameters of initial presentation exceed mild TBI, then diagnosis exceeds concussion. Concussion diagnosis

Minimum criteria to diagnose a concussion not agreed upon Screening tools helpful to determine who should be assessed by MD In cases of LOC or decline in GCS following trauma, diagnosis more clear Diagnosis is usually made on the basis of an MD assessment who is familiar with the diagnosis of concussion Some form of early onset altered mental status is commonly relied upon to make diagnosis in setting of probable inciting event normally a clinical diagnosis Presentation of concussion

Many different symptomatic complaints Some symptoms clear and some are very non-specific Some of the more clear presentations involve Loss/alteration of consciousness – cant speak coherently or cant follow instructions Lack of of surroundings – cant orient to time or place Nausea and vomiting Loss of balance/disturbance in walking steadiness Severe dizziness Significant hearing and/or vision changes/ringing ears

Concussion presentation cont…

Some associated with complaints that are less specific Headache Lethargy Emotionality Sleep disturbance Feeling of unwellness Light or sound sensitivity Difficulty concentrating Concussion: can easily be confused with

Headache/migraine Neck sprain ADHD Intoxication Depression Other psychoemotional conditions Viral illness Disrupted sleep Hormonal changes – low thyroid, monthly cycles Fibromyalgia-like conditions Many eye/ear medical problems Concussion Timeline

Normally presents immediately (no time lag) Can be initially missed in setting of more severe distracting or if alone and unaware of what is transpiring Retrospective concussion diagnoses not always reliable Can progress over hours in minority of cases. Concussion Recovery

In most cases, concussion follows a predictable course Onset of symptoms fast Usually not progressive, but in some cases can progress over minutes to hours Resolution usually follows a predictable pattern Most individuals (85% of adults) recover from concussion within 2 weeks Kids can take a little longer Almost everyone recovers within 3 months A small percentage have persistent complications

Concussion treatment

No proven treatment to augment recovery Care is supportive Should avoid early provocation and engage in a slow stepwise reintegration into activity Treatment for persistent symptoms in chronic stage may be appropriate. Evidence is not strong for specific concussion therapies. Some therapies may be worthwhile to try but others are highly contentious. Some people have risks for prolonged recovery

Many prior concussions Many concussions in a short period of time Migraine headaches before the concussion Younger age kids History of ADHD Psychiatric issues More severe concussion with loss of consciousness Post-Concussion Syndrome

Failure of concussion symptoms to recover within normal expected time No universally agreed upon definition Often thought to be polyfactorial because neurobiological effects of concussion are typically not thought to persist Ensure all factors explored: substance use, sleep, psychoemotional factors, etc… Structural Abnormalities – not a concussion

Subdural Epidural Intraparenchymal hemorrhage

Bleeding below the dura but outside brain parenchyma This is reason patients asked to be frequently awakened to ensure no progression SDH can slowly expand resulting in late progressive brain compression

Epidural Hematoma

Bleeding between the and dura Less threatening over long term because less likely to expand Late compromise is unlikely Subarachnoid hemorrhage

Bleeding into subarachnoid space (a space closer to brain tissue than a subdural hematoma) Does not usually result in progressive mass effect, but can cause other late complications Vasospasm/stroke Very severe headaches Seizures

Intraparechymal hemorrhages

Bleeding into the substance of the brain In addition to direct damage and mass effect damage, can result in late damage from hydrocephalus as well

Diffuse axonal injury

This is the type of injury being caused by rotational forces May be little visible presentation on standard neuroimaging MRI could show hemosiderin deposition (blood products in characteristic patters) as well as tiny diffuse hemorrhages Rotational forces result in mass shearing of within the brain Complications of Traumatic Brain Injury

Cognitive decrement in many domains Emotional lability/personality change/abulia/agitation Motor decline/mobility decline/gross and fine motor/balance decline Headaches Cognitive communication difficulties Dysphagia Incontinence Seizures Dizziness Care for Traumatic Brain Injury (with structural damage)

Rehab should be interdisciplinary care process Work to retrain lost neuro function/remediate deficits Training can facilitate adaptive Train to circumvent limitations May involve use of mobility aids or communication aids or alter fluid consistency etc… Manage complications Treat , treat aspiration pneumonia, treat pain, treat depression etc… Traumatic Brain Injury Recovery

In moderate to severe traumatic brain injury, most recovery usually within 1st 6 months Most plateau in recovery around 1 year post-injury Some do exhibit late recovery, but not common Traumatic brain injury

Can be devastating for Vocational performance Performance of activities of daily living Interpersonal relationships Pursuit of enjoyment of life Vertigo

Common complaint and/or comorbidity after traumatic brain injury Can be related to the neurobiological effects of brain injury itself Can be related to bone fleck in inner ear – BPPV Can be related to other factors – substance use, labyrinthitis, menierre’s,etc.. Should be distinguished from light headedmenss Helpful to have ENT input Dix Hallpike maneuver should be assessed In BPPV, Dix Hallpike maneuver is normally provocative for a matter of seconds, not more than minutes Stroke

Stroke is similar to traumatic brain injury but there are key differences Stroke is an acute onset neurological event Associated with a vascular disruption in the brain Occurs spontaneously Can be ischemic or hemorrhagic Neuro deficits correspond to neuroanatomy/pathology Term CVA (cerebrovascular event) no longer used Stroke cont…

As compared to TBI, stoke deficits are usually more focal/less diffuse There is usually better correlation between neuroanatomical involvement and clinical findings May see much more localized deficits in areas such as // Sensorimotor deficits also usually much more localized Can produce profound disability in many of same domains as TBI Causation is not usually the subject of disability litigation because not traumatically induced

Stroke management

Management of those with significant deficits should be interdisciplinary Treatment should focus on Remediation of deficits Circumvention of functional limitations Management of complications Secondary prevention Optimizing re-integration Recovery – most recovery occurs in 1st 3-6 months and usually plateau by 1 yr. Multiple sclerosis

Progressive condition with poorly understood pathophysiology arise in the (brain and ) that are demyelinating Also optic neuritis tends to occur Lesions and neurological dysfunction (that are temporally and spatially separated) Clinically and on imaging, McDonald criteria stipulates lesions separated in time and space Multiple sclerosis cont…

Disease typically progressive but follows characteristic patters Some progress continuously Some experience periods of exacerbation and remission Some progress very slowly and outlive the disease, others, rapid Often diagnosed on basis of clinical presentation and imaging (MRI with gadolinium enhancement often used) CSF analysis with Oligoclonal banding also helps corroborate No definitive treatment, but some variants may be amenable to meds to slow the disease process MS continued

Can produce multiple symptoms and profound disability Gross/fine motor dysfunction Visual loss – vibration/proprioception disproportionately affected but all modalities can be affected Pain, spasticity, Fatigue Cognitive impairment Incontinence Depression MS continued

Disability usually accumulates over years and condition is normally progressive Multiple supports are needed over years Important to recognize both physical and cognitive limitations that may arise Important to know that pain and fatigue often have biological basis in these patients and Myelopathy

Myelopathy is neurological impairment as a result of dysfunction at the level of the spinal cord. Can be a result of traumatic and atraumatic processes Atraumatic can be vascular, neoplastic, degenerative/compressive, autoimmune (ie – tranverse ), metabolic (ie – B12 deficiency), infectious (ie – epidural ) Most disability cases involve traumatic cases, but trauma complicating a pre-existing atraumatic process, particular if mechanical compression, can complicate disability scenarios Basic anatomy

Spinal cord usually ends around L1-2 vertebral body level Trauma below L2 is unlikely to produce SCI because only cauda equina at that level

SCI/Myelopathy presentation

Early on can be clinically difficult to distinguish from lower motor syndrome Should be neuroimaging corroboration – preferably MRI Initially: Reflexes depressed, tone reduced, strength reduced Late: Upper presentation predominates (may take days to weeks) Hyperreflexia Increased tone Weakness Upgoing plantar/Hoffman Traumatic SCI

Graded according to severity of injury and neurological level of injury Scale set out by ASIA Severity AIS-A – complete AIS – B – sensory complete, motor incomplete AIS – C – Motor incomplete (<50% muscles below NLI grade 3 or more AIS - D – Motor incomplete (>50% muscles below NLI grade 3 or more AIS – E - normal Neurological level of injury

Determined functionally through neurological examination Standardized sensory motor examination from the ASIA Neuro level may not be perfect match with anatomic level of imaging findings Traumatic SCI

Can involve a number of pathologies including fracture, buckling of soft tissues, mobility/transient compression without fracture, disc extrusions, ext… Visible on standard neuroimaging Often requires surgical decompression/stabilization, but not always ASIA scoring only applies to traumatic SCI

Complications of SCI

Pain Weakness Sensory loss Spasticity/contractures Incontinence/bladder /constipation Detrusor sphincter dyssenergia Autonomic dysreflexia and autonomic dysfunction Pressure ulcers Sexual dysfuction depression

Management of SCI

Often initially inpatient rehab followed by outpatient therapy May involve Cannot augment neuro recovery with therapy Therapy may augment function through strengthening of existing musculature and teaching adaptive strategies and use of assistive devices Developing transfer techniques, use of mobility aids, bladder/bowel care programs, education (bladder, bowel, AD), support surfaces, bracing, retraining gait if possible, treatment of complications Improving independence is a long and arduous struggle for those affected. Recovery from spinal cord injury

There is usually improvement over the first year following spinal cord injury Swelling subsides, some new neuro pathway may form (limited), and some strength and sensation may return Most recover occurs within the first 6-12 months. By 1-2 year neuro recovery usually plateaus.

Those with trauma to below the L2 level could have injury to the nerve roots that descend distal to the termination of the spinal cord Unlike injury to the spinal cord, this produces only a lower motor neuron syndrome Trauma is common cause, but can occur with tumors, massive disc extrusion, or anything that abruptly compresses the cauda equina Degenerative can lead to gradual onset spinal cord injury Those with pre-existing spinal stenosis are often more predisposed to injury of nerve roots with trauma.

Cauda equina syndrome

When traumatic, it is appropriate to grade on ASIA impairment scale, just as spinal cord injury. Typically needs to be managed surgically Presentation typically involves Pain Neurogenic bowel Neurogenic bladder Sexual dysfunction Variable levels of sensorimotor loss Most are mobile with braces and may not even require handheld gait aids Management/recovery of cauda equina syndrome

Care is very similar to SCI patients Proportionally more focus on bladder care, bowel care, and sexual dysfunction Autonomic Dysreflexia and Detrusor Sphincter Dyssynergia are not issues in this population Immobility rarely an issue Neurogenic pain can be problematic Course of recovery similar to that of spinal cord injury

Radiculopathy

Pathology involving the exiting from the spinal cord Most often a problem of mechanical compression from a herniated disc or narrowing of bony spaces through which the nerve passes Most often involves nerve roots exiting the cervical or lumbar spine Radiculopathy

Pain often radiates down the upper or lower limb in a manner that follows the dermatome or affected nerve root Lumbar radiculopathy also incorrectly termed ‘’, as at one time the pathology was thought to involve the sciatic nerve rather than the nerve roots Severity of sensorimotor findings dependent on severity of neurological damage Radiculopathy cont…

Sensory changes typically present as hypoesthesia in the nerve root dermatomal distribution Motor changes, if present, are lower motor neuron findings Weakness Fasciculations Decreased reflexes Low tone Atrophy Motor changes should be isolated to involved myotome Radiculopathy cont…

There is debate regarding significance of irritative focus. Discal materials, if contacting the exiting nerve root, can be irritating and produce dysesthesia as experienced in a radiculopathy without frank nerve root damage This is fairly well established in the context of full disc extrusions, as the nucleus pulposis of the disc, if contacting the nerve, can cause a significant inflammatory reaction in the involved nerve Radiculopathy – when discs contact but not compress

In cases in which a bulging (non extruded) disc is contacting an exiting nerve root (not compressing), the clinical significance is less clear. Such scenarios are common incidental findings that do not present symptomatically in many adults However, if a contacting (non-compressing) disc is producing symptomatic complaints that clearly follow a radicular pattern, clinicians will often recognize this as significant It falls into a grey area whether this should be termed radiculopathy if there is no neurological compromise Many clinicians use terms for this such as ‘radicular nerve root irritation’ or ‘irritative focus’ Diagnosis of radiculopathy

Diagnosis should not be made on the basis of symptomatic complaints alone. Symptomatic complaints may serve to prompt further investigations. Hard neurological findings may be sufficient to provide a presumptive diagnosis of radiculopathy, but it should be corroborated with investigations. MRI and radiculopathy

MRI is the ideal imaging modality to visualize nerve root pathology Allows visualization of , discs and other soft tissues, and bony tissues through which the nerve root exits. Can visualize if there is anything contacting, displacing, or compressing an exiting nerve root at a particular spinal level. In the event of a borderline compressive finding, and MRI is limited in that it cannot determine nerve root function/disfunction as a result of the questionable compression EMG and radiculopathy

Assesses neurophysiological function to determine if there is any acute or chronic nerve damage involving the nerve root in question Can identify a nerve root being actively damaged fairly accurately Can determine if there was old damage to a nerve root that has since recovered, but cannot place a definitive date on when that recovered nerve damage had occurred. It is possible to miss a radiculopathy if the EMG is done less than several weeks after date of onset/injury Cannot rule out a non-damaging irritative focus Management of Radiculopathy

Many will recover within 3-6 months after onset. Bulging and herniated discs can at least partially resorb spontaneously and the pressure on nerve roots can be relieved In the first 3-6 months, supportive care is preferable Pain management: Tylenol, NSAIDs, , possibly opiates Physiotherapy: to core strengthen and to improve mobility/range Core strengthening may act as a physiological splint to reduce the pressure on exiting nerve roots that produces the bulging/herniation Further management of radiculopathy

Injection treatments may have a role Epidural cortisone injections may be helpful in pain control Helps reduce swelling/inflammation of an irritated nerve root Cortisone injection cannot help reduce nerve compression Cortisone injection is predominantly a symptomatic measure No clear timeline when it is appropriate to trial a cortisone injection, but usually not considered until other conservative measures have failed Surgical decompression

May be role for surgical decompression if If the symptoms no not resolve within 6 months Not responsive to other measures The compression is well established with investigations The pain is not back dominant If there are any hard neurological findings Peripheral

Peripheral nerve injuries usually refer to nerve injuries below the level of the plexus Can be compression injuries or lacerations Lacerations are acute event Compressions can be acute or chronic Carpal tunnel syndrome a classic example of a peripheral nerve injury Peripheral nerve injury cont…

Nerve compression or crush injuries are often graded depending on whether the only is damaged, the is also damaged, or whether the entire nerve is damaged including surrounding . Lacerations are acute events that produce pain and sensorimotor loss in the distribution of the affected nerve territory.

Demyelinating injuries

Many nerves (particularly motor and vib/prop nerves) are surrounded by a myelin sheath that aids in conduction of signals In compressive injuries, myelin is usually the first thing to get damaged This is also the most transient injury as myelin can regrow in a few weeks Axonal injuries

When a nerve is injured at the level of the axon, the nerve usually dies back to the point of injury The nerve can regrow, but does so very slowly, only 1mm/day A re-growing nerve may never reach its target destination if it forms a neuroma or some other aberrancy in regrowth Severe nerve injuries

If a nerve injury affects the axon and surrounding connective tissues (as is the case in most lacerations), the nerve cannot regrow. The nerve needs the sheath of connective tissue to guide its growth May require a surgical procedure to facilitate regrowth with varying degrees of success Successful regrowth can take months to > year Usually results in some permanent loss of strength and sensation at minimum Some motor recovery may occur in the absence of regrowth due to collateral sprouting (provided some of the nerve remains intact) Nerve injury diagnostics

There has been growing role for imaging modalities in the diagnosis of peripheral nerve injuries Ie – US now used to visualize median nerve swelling in carpal tunnel syndrome EMG is still gold standard as this can detect degree/severity of physiological dysfunction and identify if demyelination or axonal damage

Nerve injury causation

Question often arises as to whether trauma event could be responsible for peripheral nerve injury In laceration – yes In acute crush injury – yes In acute compression from hematoma, fracture, or compartment syndrome - yes In entrapment neuropathy – maybe, but usually not Entrapment neuropathies

Most common form of peripheral neuropathies Classically chronic, insidious problems that are not associated with particular traumatic event Rarely associated with soft tissue injury Exception would be a fracture that alters bony anatomy Ie – wrist fracture that causes change to carpal tunnel/path of nerve that accelerates medial nerve compression at that level. Management of entrapment neuropathies

Supportive care – medications to manage symptoms Functional Bracing – to compensate for muscle weakness Non-Functional Bracing – for postural correction to mitigate ongoing nerve compression (ie – night wrist splints for carpal tunnel syndrome) Cortisone injection – to reduce nerve swelling and help restore function in compressed nerves (only useful for certain nerve injuries, such as carpal tunnel syndrome and only for mild-mod cases) Surgery – for nerve decompression and/or transposition or repair Complex regional pain syndrome

Type 2 CRPS (formerly known as causalgia) is CRPS developing as a sequelae of a peripheral nerve injury Type 1 CRPS is that which develops under all circumstances other than that of a peripheral nerve injury CRPS 1 may also arise as a result of traumatic injury/fracture, stroke, and other causes CRPS continued

CRPS is a pain syndrome that has an abundance of objective findings Characterized by a combination of characteristic pain symptoms and characteristic ‘dysautonomic’ symptoms Pain symptoms include Pain Hyperalgesia – increased pain to painful stimuli Hyperesthesia – increased sensation in genral – pain in response to non-painful stimuli Hyperpathia CRPS Dysautonomia cont…

The diagnosis of CRPS can only be made with coexisting local features of dysautonomia Dysautonomic features in CRPS affecting the limb will most typically be confined to the distal portion of the limb These include: Swelling – common Temp change – warmth most common Dyscolouration – erythema most common Changes in sweat and oil production Can also sometimes see changes in skin, nails, and hair distribution CRPS cont… CRPS diagnosis

Diagnosis is clinical Imaging may be used to corroborate characteristic findings, but can not rule in or out (characteristic findings on x-ray, bone scan) Investigations usually used to rule out differential diagnoses ( ie – DVT, fracture, ) Various diagnostic criteria exist (IASP criteria and Budapest criteria), but none have gained widespread acceptance/integration Generally diagnosis is made based on the presence of characteristic pain findings and characteristic dysautonomic features. CRPS management and prognosis

Prognosis varies from complete resolution to indefinite persistence with severe symptoms Many physical and medical measures can be utilized in the management, with varying degrees of success Physical: active movement and physio, contrast baths, mirror therapy, desensitization massage Medical: , neuropathic pain meds, prednisone, topical agents, intravenous lidocaine, sympathetic blocks Surgical: Sympathectomy Peripheral neuropathies

Many types of peripheral neuropathies Small fiber, axonal, demyelinating, etc… Usually not traumatically induced with the exception of ICU neuropathy, which could be a sequelae of massive trauma. Can be a severe cause of disability Can be gradual onset – ie diabetic length dependent peripheral neuropathy Can be abrupt in onset – ie – Guianne Barre syndrome Most peripheral neuropathies are permanent Diagnosis of PN

Clinical diagnosis EMG diagnosis (EMG cannot detect purely small fiber neuropathies) CSF analysis – usually for rapid onset peripheral neuropathies as protein elevated in GBS Quantitative sensory testing – may be helpful in small fiber neuropathies Nerve biopsy – not a routine investigation, but can be helpful in confirming pathology, particularly in those not not EMG detectible Etiology of peripheral neuropathies

Most are metabolic (DM, TSH, B12) Can be exposure to toxins or abuse Can be autoimmune (ie – GBS, CIDP, associated with vasculitis) Can be genetic progressive disorder (ie – CMT) Can be sequelae of phys/med complications – ICU neuropathy

Peripheral Neuropathy Presentation

Depends on type of peripheral neuropathy May affect strength and coordination and spare pin/temp sensation May only affect pin sensation May affect all sensory modalities, coordination, and strength Management

Identification and management specific to underlying condition Pain management for those with neuropathic pain Handheld gait aids for those with loss of balance Orthoses for those with for those with severe decrement in mobility.