Sensory-Motor Exam

Neuroanatomy of Tone

- Reticulospinal tracts used for muscle tone. Motor tracts - Pontine reticulospinal: Facilitates VHC. AKA ventral reticulospinal tract. POSITIVE motor - Medullary reticulospinal: Inhibits VHC. AKA dorsal reticulospinal tract. Receives info from cortex - Lateral vestibulospinal: Stimulates extensor motor neurons in the legs. Maintains upright/balanced posture. Receives input from cerebellum. POSITIVE motor - Cortex damage: Leads to increased motor activity due to unrestricted PR and LVS tracts when MRS tract damaged -> Results in hypertonus

Spasticity v Rigidity

- Rigidity is seen in EXTRApyramidal disease (PD) - Same resistance in all directions - Not velocity dependent - Cogwheel rigidity: Ratchet-like movement; joints appear to click rather than move smoothly. Tremor superimposed - Lead pipe rigidity

Frontal Release Reflexes

- Rooting: Baby turns face toward stimulus - Sucking: After following stimulus, baby is able to drink milk - Snout: Pouting of lips with slight tap to closed lips - Glabellar: Closing the eyes when tapping b/w the eyebrows - Palmar: Object placed in hand, may stroke hand - Palmomental: Stroking thenar eminence causes contraction in region of mental nerve

Testing Brachial Plexus

- Shoulder abduction and adduction - Chicken dance - Elbow extension and flexion, tricep and bicep muscle - Wrist extension and flexion - Finger flexion: Weakness may be more apparent here. Pts may complain of issues gripping pens or poor handwriting - Finger abduction

UE Tone

- Starting distance and then proximal - Wrist extension and flexion - Elbow extension and flexion - Shoulder abduction and adduction

Other Ways to Test Dorsal Column

- Stereognosis: Using tactile info to recognize an object. Absence of auditory or visual input - Graphesthesia: Ability to recognize writing on the skin

Abnormal P2PTPVS

- Stocking glove sensory loss (B/L) and polyneuropathy - Will have reduced pinprink and temp sense - But also dec in vibration threshold and proprioception

Testing Vibratory Sense

- Tuning fork place the vibrating instrument on a bony prominence - Compare left and right, distal and prox, may vary the intensity of vibration - Pallesthesia: Inability to perceive vibration

Testing Conscious Temp

- Using a cold tuning fork or transilluminator - Touch face and 4 limbs - Ask if they can feel temp and if feels same B/L

Muscle Strength Scale

- 0/5: No contraction - 1/5: Muscle can flicker, but no movement - 2/5: Can move, but not against gravity - 3/5: Movement against gravity but not against resistance by examiner - 4/5: Able to move against some resistance - 5/5: Normal

UE Reflex

- 3 reflexes - Biceps: Arm across body. Place thumb over bicep tendon. Tap with reflex hammer - Tricep: Arm across body. Tap w reflex hammer - Brachioradialis: Arm across body. Tap with hammer 3 inches above wrist. Observe for supination (palm turns up) -> supinator reflex

LE Reflex

- 3 reflexes - Patellar: Leg relaxed with no weight (dangle). Tap tendon with reflex hammer. Should cause extension - Ankle: Leg dangles. Foot in slight flexion. Tap tendon with reflex hammer. Should produce flexion - Plantar: Run handle of reflex hammer along the sole of the foot. No response of toes inward is normal and negative in adult. Fanning of toes normal in children up to age 24 months

Hypertonia

- Accompanied by pyramidal tract dysfunction, increased tone is often in form of spasticity

Frontal Release Signs

- Also seen in babies but disappear with age - Localize to frontal lobe - May result in damage to frontal lobe in adults

Complete Loss

- Anesthesia: Pain, temp, touch, or vibration - Analgesia: Specific to sensation of pain

Guillain-Barre Syndrome

- Autoimmune demyelinating disease - May be triggered by infection. Bacteria in uncooked chicken - Cross reactive antibody may attack axon or schwann cell - Tx: IVIG, plasmapheresis

Stocking Glove Sensory Loss

- B/L - Polyneuropathy - Caused by "length dependent" axonal neuropathies - Causes: DM, vitamin B12 low, or drug induced by chemo - Takes time to develop. Legs progress before hands. Usually not associated with weakness -> If hands and legs affected in short time: Suspect guillain barre. Weakness and tingling in extremities are first signs. May progress to paralysis. Requires hospitalization

LE Testing Proprioception

- Bend the toe by holding on the sides - Move the pts toe manually up and/or down - With eyes closed, ask the pt to report if their toe is bent up or down

Testing 2-pt Discrimination

- Best done with caliber - Fine-point object and note when the pt is able to recognize 2 points - Compare to other side - Discrimination greatest on lips > palms > shins

Abnormal Pain/Temp

- Cortical lesion: Loss on one side. Contra to brainstem, thalamus, or cortex lesion. Loss follows FUTL. Loss involving most of an extremity or trunk

Testing Reflexes

- DTR checked w hammer - Limbs should be relaxed - Look for symmetry b/w two sides - Graded from 0-5: 5/5 is NOT normal - DTR scale: - 0/5: Absent - 1/5: Trace reflex seen - 2/5: Normal - 3/5: Brisk - 4/5 Non-sustained clonus - 5/5: Sustained clonus

Babinski Sign

- Descending corticospinal stop spread of sensation from one nerve root to another - If corticospinals are damaged, sensory info from S1 dermatome (causes toe extension) spreads to L4 and L5 which are responsible for toe flexion - Damage to UMN - Present in babies due to lack of myelination

Abnormal P2PTPVS vs Pain and Temp

- Disproportionate loss between these two tracts tends to occur in diseases of the dorsal columns of spinal cord - Tabes dorsalis, vitamin B12 deficiency, MS

Strength Issue in UE

- Drift: Pt holds up arms and closes eyes. Observe for any pronator drift (palm turns down). Touches bottom of hand may accentuate effect

Testing Tone

- Functionally assessed as the resistance to passive movement - Ask the pt to relax - Passively move each limb at several joints to get a feeling for any resistance or rigidity

Dysfunction of CP&T

- Hemianalgesia: Suggest cortical lesion - More focal: Peripheral lesion. May localize to dermatome - Dermatome: Areas of skin that are innervated by a single nerve root - Ex: Radiculopathy (pinched nerve) or sciatica -> May have associated weakness -> May not cause significant sensory loss but often characterized by severe stabbing/piercing pain. May be worsened by coughing, moving, or sneezing - Spinal cord lesion may be B/L. Cape distribution sensory loss (like they have a cape on)

Strength Dysfunction

- Hemiparesis suggest cortical lesion - Focal issues suggest more peripheral lesion, may localize to myotome

Diminished Sense

- Hypoesthesia: Pain, temp, touch, or vibration - Hypalgesia: Specific to sensation of pain

Stretch Reflex

- If muscle is stretched, reflex contraction occurs - Damage in cortex: Results in less inhibition of reticulospinals -> more stimulation of reflex

Inspection

- Inspect several individual muscles to see if muscle wasting or atrophy - Damage to UMN results in negative and positive signs -> Negative: Wasting atrophy, paralysis or paresis -> Positive signs: Hypertonia and hyperreflexia

Wallenberg's Syndrome (lateral medullary)

- Ipsi loss of pain and temp to head (spinal tract and nuc of V) with contra loss of pain and temp in the body (lat spinothalamic tract) - PICA infarct

LE Tone

- Knee extension and flexion - Ankle plantarflexion and dorsiflexion (plantar is toward floor, dorsi is toward air)

Lumbosacral Plexus Testing

- Knee flexion and extension - Foot flexion and extension

Cape Distribution Sensory Loss

- May be due to syringomyelia - Cystic cavity within the spinal cord - May be associated with arnold chiari malformation - Ocular signs: Horner's, nystagmus, papilledema

Strength

- Muscles ability to contract and create force in response to resistance - Testing: Check for weakness of UE and LE - Compare strength and ability of each muscle group w/ the contralateral side looking for any asymmetry

Myotome

- Muscles innervated by single nerve root - Cervical plexus: C1-4; diaphragm, shoulder, and neck - Brachial plexus: C5-T1; UE - Lumbosacral plexus: L1-L5, S2; LE

Tone Definition

- Not well defined - Muscle contraction and relaxed state - CNS provides constant innervation for extensor and flexor muscles. This unconsciously provides proper posture

Spasticity

- Often has resistance in one direction than other - Velocity dependent (more noticeable with fast movement) - Clasp knife: Response gives resistance first then rapidly gives way

Miller Fisher Syndrome

- Ophthalmoplegia, sensory ataxia, areflexia - 5% of all GBS cases - 96% positive for anti-GQ1b antibodies - Abnormality in sensory conduction, although the underlying pathology is not clear

Vitamin B12 Deficiency and Eyes

- Painless, progressive, B/L, and often symmetric optic neuropathy - Often has dec VA, CV, and cecocentral VF defects - ON pallor temporally but may be diffuse - When deficient: Build up of methylmalonyl CoA which interferes with myelin sheath formation in 2 ways -> Competitive inhibitor of malonyl CoA in fatty acid synthesis -> Propionyl CoA can sub for acetyl-CoA which results in unstable membranes - Neuro effects: Peripheral neuropathy, poor proprioception, weakness, ataxia, cog decline

Testing Conscious Pain

- Pinprick test: Safety pin, sharp object - Lightly touch the face and 4 limbs - Ask if prick feels same on both sides - Demonstrate test first then perform with eyes closed - Start distal and then move proximal

Romberg Test

- Proprioception - Pt stands with feet together - Closes eyes, avoids visual input helping loss of position sense - Pt can be tapped to see if they can maintain their balance - Sway/fall is indicative of abnormal proprioception. Pt may note they lose balance in dark room

Facial Pain

- Pt may have abnormal face sensation w contra abnormal pain sensation -> Does not localize to cortex but to brainstem (medulla) - CN V: -> Mesencephalic nuc: Reflex proprioception to teeth/jaw. Midbrain -> Chief sensory pontine nuc: Discriminative touch from face. Pons -> Spinal trig nuc: Receives pain, temp from ipsi face (and crude touch). Medulla

Testing Fine Motor

- Rapid finger tapping - Roll hands forward and backward