PERIPHERAL NEUROPATHIES DIFFERENTIAL DIAGNOSIS AND PROGNOSIS J Ned Pruitt II Professor of Neurology Medical College of Georgia/Georgia Regent s University
OBJECTIVES Nomenclature Anatomic distribution Anatomic classification of neuropathies Physiologic classification of neuropathies Hereditary versus Acquired Neuropathies Diagnostic Algorithm
OBJECTIVES Types of Neuropathies Long term prognosis Prognosis for severe disability? Premature mortality Treatment Options Effect on morbidity and mortality Peripheral Neuropathy -?????????
ANATOMIC DISTRIBUTION Where? Distal and Symmetrical Length Dependent Inherited Charcot-Marie-Tooth toxic/metabolic Diabetes, thyroid dx, monoclonal gammopathies Asymmetric = Focal or Multifocal Non Length Dependent Polyradiculoneuropathies - AIDP (Guillain-Barre Syndrome) Plexopathies infectious Sensory ganglionpathies paraneoplastic Multiple mononeurpathies (Mononeuritis multiplex) - vasculitis
ANATOMIC CLASSIFICATION Large fiber - Motor, Position Sense/Vibration Small Fiber Sharp Pain/temperature, Autonomic Motor Sensory Sensory/Motor Autonomic
TIMING When? Acute or Subacute Immune-mediated Infectious Slow onset Inherited Toxic/metabolic idiopathic
Diabetic Neuropathy Large Fiber Presentation Motor > Sensory symptoms Feet usually affected first Vibration perception loss Position sense loss Deep-seated gnawing/aching pain Muscle wasting and hammertoe development May interfere with activities of daily living related to balance and ambulation Abnormalities readily detected by Nerve Conduction Studies
Diabetic Neuropathy Small Fiber Presentation Sensory >> Motor symptoms Early: Pain and hyperalgesia Later: Loss of sensitivity to Heat/Cold Light tough and Pin Prick Autonomic symptoms: Orthostatic symptoms Impotence Blurred vision Constipation Predisposes to diabetic foot ulcers Nerve conduction studies may NOT detect abnormalities
Asymmetric Neuropathy Focal or Multifocal Variable Motor and Sensory Symptoms Variable Etiologies Hereditary: HNPP Acquired:CIDP Antibody Mediated
INHERITED NEUROPATHIES Characteristics Motor > Sensory symptoms Distal, Symmetric Insidious/gradual onset with slow progression + Family History, foot deformities/ulcers Charcot-Marie Tooth Disease Hereditary SensoriMotor Neuropathy HNPP (Hereditary Neuropathy with liability to Pressure Palsies)
TOXIC/METABOLIC Characteristics Sensory>Motor Symptoms Distal, symmetric History of risk factors, exposures Diabetic Uremic Alcohol B12 or B1 deficiency Hypothyroid Medications Chemotherapy agents, Amiodarone
IMMUNE MEDIATED NEUROPATHIES Characteristics Variable Motor and Sensory Symptoms Not distal nor symmetric Symptoms of vasculitis or systemic illness Non Vasculitic AIDP (GBS) CIDP Multifocal Motor Neuropathy Sarcoid Sjogren s Vasculitic Polyarteritis Nodosa Wegner s Churg-Strauss SLE RA
ASSESSMENT Electromyogram and Nerve Conductions Laboratory Testing Skin and Nerve biopsies
EMG/NCV Nerve Conduction Testing Axonal Vs Demyelinating Electromyography Denervation Muscle pathology Abnormal electrical discharges Neuromuscular Conduction defects
LABORATORY TESTING Complete blood count Comprehensive metabolic panel Erythrocyte sedimentation rate Fasting blood glucose level, Hgb A1C Thyroid-stimulating hormone level Vitamin B12 Glucose tolerance test, A1C level HIV Hepatitis panel Lyme antibodies? RPR, VDRL Urine for Heavy metal toxicity, Urine and serum protein electrophoresis with immunofixation Angiotensin-converting enzyme levels Antinuclear antibodies, P-ANCA, C-ANCA
NERVE/SKIN BIOPSIES Inflammatory Vasculitis: Inflammation; Differential fascicular involvement; Edema Perineuritis Demyelinating Disorders Immune: CIDP Hereditary: Metachromatic Leukodystrophy (MLD) Hereditary Disorders Giant Axonal Neuropathy Multi-Infarct dementia (CADASIL) Neuroaxonal Dystrophy CMT General Tomaculous neuropathies: HMSN, especially HNPP; CMT 4B CMT 4C Metabolic disorders with distinctive changes & storage inclusions Fabry's Krabbé Metachromatic Leukodystrophy (MLD) Systemic Disease: Leprosy; Amyloid; Sarcoid Toxic (with characteristic features, e.g. amiodarone)
DIAGNOSTIC ALGORITHM
PROGNOSIS Hereditary Neuropathies Charcot-Marie-Tooth Disease Very slow progression of motor problems AFOs to Canes to Rolling Walkers to Scooter over decades No decrease in life span
PROGNOSIS Toxic/Metabolic Neuropathies Most disability due to pain control and their associated medications Occasional disability related to gait problems Neuropathy itself does not contribute to mortality but can to morbidity due to falls.
PROGNOSIS Immune Mediated Neuropathies Isolated Neurologic Immune Neuropathies Highly variable CIDP MMN (Multifocal Motor Neuropathy) Vasculitis Morbidity and mortality related to underlying disease
TREATMENT OPTIONS Hereditary Neuropathies Support and Anticipation of Disability
TREATMENT OPTIONS Toxic/Metabolic Neuropathies Removal of the toxin (if Possible) Chemotherapy HIV meds Control of the underlying metabolic problem or replacement of nutritional deficiency
TREATMENT OPTIONS Immune Mediated Neuropathies IV IgG Steroids Azathioprine MTX Cyclophosphamide
PERIPHERAL NEUROPATHY Questions to ask Hereditary or Acquired? If Acquired then what is the etiology? Conclusions based on???????