Approach to a case of motor and sensory disorders

APPROACH TO A CASE OF MOTOR AND SENSORY DISORDERS

Introductory Lecture Series

Dept. of Medicine

IV Term

Dr C Khati

Why Motor and Sensory Disorders together?


Shared routes


Shared routes

Identification by the company kept

Overall Objective

To identify

1. Where is the lesion?

Neuro-Anatomical Localization

2. What is the lesion?

Pattern Recognition

Etiological Diagnosis

Complex Brain Processing

CC

HISTORY

EXAMINATION

How to go further?

• Basic Neuroanatomy

• Basic Pathophysiology

Symptom Based Approach

Pattern Recognition

Etiological List

How to go further?




Pattern Recognition

Etiological List

How to go further?




Pattern Recognition

Etiological List

Specific Learning Objectives

• Recapitulate Neuro-anatomy

• Recap Neurophysiology

• Clinical Features (Symptom based approach)

• Pattern Recognition (Symptoms and signs)

• Etiological List

• Investigation List

• Take Home Messages

• Videos/ Case studies

Neuroanatomy

• Motor Pathways

– Pyramidal Tract

– Motor unit

• Sensory Pathways

– Dorsal Columns

– SpinothalamicTract

• Reflex Pathway

Neuroanatomy

• Motor Pathways

– Pyramidal Tract

– Motor unit


– Dorsal Columns


• Reflex Pathway

Neuroanatomy

• Motor Pathways

– Pyramidal Tract

– Motor unit


– Dorsal Columns


• Reflex Pathway

Motor Pathway

• Pyramidal or

Corticospinal tract

MOTOR PATHWAY

UMN Lesion

1. Weakness

2. No atrophy (No fasciculation)

3. Increased tone

4. Increased DTR

5. Extensor Plantar (Babinski Positive)

Motor unit – a motor neuron and all the

muscle fibers it innervates

• Motor unit – a motor neuron and all the

muscle fibers it innervates

Motor unitStructural Organization of PNS in

Region of a Spinal Nerve

LMN Lesion

• All lesions involving a motor unit are LMN

(Lower Motor Neuron) lesions

1. Weakness

2. Atrophy (with fasciculation &/fibrillation)

3. Decreased tone (hypotonia)

4. Decreased DTR (hyporeflexia)

5. Flexor Plantar (Downgoing toes)

Extra Pyramidal System

(Basal Ganglia)

1. Chorea

2. Athetosis

3. Hemiballismus

Cerebellum

1. Intention tremor

2. Ataxia

3. Nystagmus

4. DTR/tone ipsilaterally

5. Asthenia

Ascending Pathways

• Dorsal Column/Medial

Lemniscal Pathway:

Touch, vibration, proprioception

• Anterolateral System:

Spinothalamic tract- pain & temp

At medulla

Dorsal column-Medial Lemniscus Pathway

Ascending tracts & their crossings

• Dorsal Column: As internal arcuate fibers in

Medulla

• Lateral Spinothalmic tract: Fibers cross at the

same level of segment where they enter the

spinal cord

Reflexes

• Superficial reflexes:– All sup reflexes lost in pyramidal lesions

– Local reflex lost to a local arc lesion (eg cremasteric

reflex)

• Deep Tendon Reflexes– Exaggerated: Pyramidal lesions

– Absent/Reduced: LMN lesions

– Nerve lesions (e.g.Radial N lesion - triceps jerk C7-8)

Reflexes



reflex)




Reflexes



reflex)




STRETCH REFLEX & RECIPROCAL INNERVATION

Neurophysiology

• Impulse generation

• Impulse conduction

- in axons

- across synapses

• Energy dependant electrochemical gradient

• Neurotransmitters

Neurophysiology



- in axons

- across synapses



Neurophysiology



- in axons

- across synapses



Neurophysiology

• Hierarchy of control mechanisms

– Posture and baseline muscle tone

– Superimposed movement

– Coordination for targeted movement

• UMN regulatory control on LMN (inhibitory)-modulates tone and reflex

– Monosynaptic axn- withdrawal response

– Polysynaptic axn- for coordinated action

Neurophysiology








Neurophysiology








Pathophysiology

• Larger fibres

• Smaller fibres

Pathophysiology

• Neuronal Necrosis (energy failure)

• Apoptosis (programmed death- gradual)

• Axonal Degeneration

• Demyelination

Pathophysiology

• Neuronal Necrosis (energy failure)

• Apoptosis (programmed death- gradual)

• Axonal Degeneration

• Demyelination


Symptom Based Approach I System Disorder

Sensory (-)Numbness (Hypoaesthesia)(+)Tingling (dysaesthesia)(+)Pain (Neuralgia/ Poorly localised)(+)Hyperpathia &Causalgia (non sensory stim.)


Sensory (-)Numbness(+)Tingling (+)Pain(+)Hyperpathia &Causalgia (non sensory stim.)

Motor •Weakness – Proximal vs Distal, Regional•Movement Disorder- Initiation, Coordination, Tremors, spasms/ jerks









Motor •Weakness •Movement Disorder

Associations & Accompaniments

•Sphincter (incontinence/ retention)•Cranial Nerves• EPS/ Cerebellum•Autonomic disturbance





















Symptomatic Approach II

Temporal Profile Condition

Continuous •Static•Progressive•Improving

VascularInfections and Para-infectious ProcessesDegenerativeDemyelinatingTumorTraumaMetabolicNutritionalDrugs and Toxins

Episodic•Intermittent•Remittent

•Abnormal Movement•Hypo and Hyperkalemia•Porphyria•TIA•Seizure•Demyelination

























Present Illness

• Symptoms

Clarify SymptomsOnset, Duration and Progression

Onset

Some Disability

Pattern List• Hemiplegia-

• Crossed

• Uncrossed

• Quadriplegia

• Paraplegia

• Plexuspathy

• Radiculopathy (mono/poly)

• Monoplegia

• Muscle groups

• Hemisensory loss

– Complete (Thalamus)

– Harlequinn (Brain Stem)

• Sensory loss below a level

• Brown Sequard (hemi-cord)

• Dissociated/suspended loss


• Peripheral Neuropathy

• Mononeuropathy

• Mononeuropathy Multiplex


• Crossed

• Uncrossed

• Quadriplegia

• Paraplegia

• Plexuspathy


• Monoplegia

• Muscle groups









• Mononeuropathy



• Crossed

• Uncrossed

• Quadriplegia

• Paraplegia

• Plexuspathy


• Monoplegia

• Muscle groups









• Mononeuropathy



• Crossed

• Uncrossed

• Quadriplegia

• Paraplegia

• Plexuspathy


• Monoplegia

• Muscle groups









• Mononeuropathy



• Crossed

• Uncrossed

• Quadriplegia

• Paraplegia

• Plexuspathy


• Monoplegia

• Muscle groups









• Mononeuropathy


http://www.doereport.com/enlargeexhibit.php?ID=4941

http://www.doereport.com/enlargeexhibit.php?ID=4941

PPeripheral

Neuropathy

Sensory loss below a level

COMPLETE CORD TRANSECTION

•Sensory: All sensations

impaired below level oflesion

• Motor: Quadriplegia/

Paraplegia depending onlevel of lesion

UNILATERAL HEMISECTION OF CORD(Brown Sequard Syndrome)

• Motor: I/L UMN

• Sensory: I/L sensation loss

• Pain: C/L Pain & Temp. Loss

Sensory loss below a level

LESIONS AFFECTING SPINAL CORD CENTRALLY

• Seen in Syringomyelia- cavitationcentral grey matter of spinal cord

• Sensory: Spinothalamic are first tobe affected followed by dorsal column

• Motor: Affected last- initially LMNthen UMN type









Sensory -1st Order NeuronSpinothalamic

• Crude Touch

• Pain

• Temperature

• Superficial reflexes (afferent)

Dorsal Column

• Fine Touch

• Pressure

• Stretch

• Position

• Vibration

• 2 point discrimination

• Deep reflexes (afferent)

Thalamic Sensory Features(2ndOrder neuron)

• Deep seated poorly localised pain

• All modalities of sensations

• Always opposite side

Cortical Sensory Features(3rd order Neuron)

• Hemi- neglect

• Hemi –inattention

• Inability to localise touch

• Agraphaesthesia

• Asteriognosis

• 2 Point -Discrimination

Motor Symptoms

• Weakness – Reduction in normal power of one or more muscles

• Proximal Vs Distal

• Groups vs Regions

• Plegia vs Paresis

Motor Symptoms

• Weakness

• Fatiguability- Inability to sustain activity (comparative)

• Twitching in muscles (fasciculation)

• Spasms and Cramps

• Myalgias

• Dyskinesias

• Imbalance/ unsteadiness

• Difficulty in movement

Motor SignsUMN

• Weakness(Pyramidal / regional distribution)

• No Atrophy

• Spasticity (Ridgity in EPS)

• Exaggerated Deep Tendon Jerks (DTJs)

• Extensor Plantar

• Tremors (in EPS and Cerebellar involvement )

• Gait

LMN

• Weakness (Segmental / distal distribution)

• Atrophy

• Flaccidity (Decreased tone)

• Diminished DTJs

• Flexor Plantar

• Fasciculations

• Gait

Motor SignsUMN


• No Atrophy





• Gait

LMN


• Atrophy


• Diminished DTJs

• Flexor Plantar

• Fasciculations

• Gait

Motor SignsUMN


• No Atrophy





• Gait

LMN


• Atrophy


• Diminished DTJs

• Flexor Plantar

• Fasciculations

• Gait

Gait

Etiological List• Vascular

• Infections and Para-infectious Processes

• Degenerative

• Demyelinating

• Vasculitis

• Metabolic

• Nutritional

• Tumor

• Trauma

• Drugs and Toxins

Investigations

• Routine Haematology and Biochemistry

• Imaging and Contrast Studies

• Nerve Conduction Studies

• CSF

• EMG

• Nerve Biopsy

• Muscle Biopsy

• Special Tests- B12 assay, Copper, Neuronal/receptor antibodies, Serology for infections, Hormone assays, Porphobilinogens, Immunological &Tumour Markers, etc

Take Home Messages: Shared routes

MOTOR• Cerebral Cortex• Internal Capsule• Mid Brain (peduncles)• Pons • Medulla• Spinal Cord• Nerve Roots• Plexuses• Peripheral Nerves• Motor end plates

• SENSORY• Cortex• Internal Capsule• Thalamus• Pons• Medulla• Spinal Cord• Roots• Plexuses/Cords• Peripheral nerves• Receptors


































Take Home Messages: Different Directions

• MOTOR- Descending . SENSORY -Ascending

Take Home Messages- Motor System

Motor System consists of 2 neurons (UMN &LMN)

• Pyramidal Tract (UMN) .• Motor Unit (LMN)

• Extrapyramidal Tracts

• Cerebellar Pathway

Take Home Messages –Motor System

Only 1st Order neurons cross (UMN)

• Lesions before the crossing of pyramidal tract cause contra-lateral features

• Lesions after the crossing of pyramidal tract cause ipsi-lateral features


• Alteration in bulk, tone, power and reflexes help in pattern recognition and to differentiate between UMN and LMN lesions

Motor testing is objective

More accurate


• Alteration in bulk, tone, power and reflexes help in pattern recognition and to differentiate between UMN and LMN lesions

Motor testing is objective

More accurate

Take Home Messages –Sensory System

Sensory System consists of

• 3 neurons (1st, 2nd and 3rd order neurons) and

• 2 Pathways- carrying different sensations

• Spinothalamic

• Dorsal Columns

Beyond Thalamus the pathways merge



• 3 neurons (1st, 2nd and 3rd order neurons)


• Spinothalamic

• Dorsal Columns






• Spinothalamic

• Dorsal Columns






• Spinothalamic

• Dorsal Columns



Only 2nd order neurons cross in both pathways

• Spinothalamic- at spinal level

• Dorsal Columns –at medulla

• Lesions before the crossing cause ipsi-lateral features

• Lesions after the crossing cause contra-lateral features

• Throughout the length of the spinal cord, both sensory pathways run on different sides of the cord

• Complete anesthesia is a rare finding


































• Clinical features help in pattern recognition and differentiate Dorsal Column from Spinothalamic lesions.

Sensory testing is subjective

Less accurate


• Clinical features help in pattern recognition and differentiate Dorsal Column from Spinothalamic lesions.

Sensory testing is subjective

Less accurate

Take Home Messages – Motor & Sensory • Gait is an important clue to localization

• Being part of the reflex arc, involvement of reflexes is seen in both

• Accompanying features (motor/sensory/ cranial nerve/ cerebellar/EPS/ autonomic) also help in localisation

• Temporal profile and other history give clue to the etiology













Case1 : 25 year old soldier on leaveBrought by relatives

• Weakness of all 4 limbs X 5 days• Difficulty in breathing X 1 day

• Noticed weakness of left LL on waking up. A few hours later similar complaint started in the right LL. A day later same problem developed in the upper limbs too. There has been rapid worsening. For the past 2 days he is unable to get up from the bed. Since yesterday he has developed difficulty in breathing. No cough……

• No sensory complaints. No suggestion of cranial nerve involvement/ seizures/ bowel & bladder disturbances

• Diarrheal illness 2 weeks ago

25 year old soldier on leave

• Clinically- T 99 degree F• Pulse 120/ min• BP 160/100• Tachypnea- shallow respiration• Chest expansion 1 cm

• Wasting• Decreased tone• Grade 0 to 2 power• Areflexia- all 4 limbs

25 year old soldier

• Where &

• What is the lesion ?

25 year old soldier

• Acute, Asymmetric, Areflexic, Quadriparesis(Polyradiculopathy)

• Post infective

Gullian Barre Syndrome

25 year old soldier

• What are the urgencies?

25 year old soldier

• Respiratory Neuromuscular Failure

• Dysautonomia

Case 2: 30 year old lady

• Burning pain like a band on the right side of the chest X 2 days

• Few blisters over the same area- this morning

• What?

• Where?

Case 3: 45 year old Hypertensive

• Weakness left side of body X 6 hours

• Sudden onset, while sitting at the table, progressed rapidly over 1 hour, no improvement

• Where is the lesion?

• What is the lesion?


What if-

• Was irregular with medication ?

• Had an argument with his wife ?

• Had intense headache preceding the event ?

• Had a seizure (focal with secondary generalization) on the way to the hospital ?


• BP 200/120 mm

• Pulse 56/ min regular

• Resp20/ min

• Altered sensorium

• Bulk & tone- equal

• Left sided hemiparesis; power grade I

• Exaggerated deep tendon jerks• Neck stiffness

Diagnosis

• Right Sided Hemiparesis

• Intracerebral Hemorrhage

• Hypertensive Etiology

Case 4: 18 year old girl

• Fever X 1 Month

• Backache X 1 month

• Numbness and weakness of both lower limbs X 7 Days

• Severe burning pain around the middle X 7 Days

• Inability to control urination X 2 Days


• Thin built, poorly nourished

• T 100 degree F

• P 110/ min

• BP, Resp- N

• Pallor +

• Cervical matted lymphadenopathy +

• Smell of urine+


Motor:

• Lower Limbs

• Bulk equal

• Tone increased in both lower limbs

• Power grade 0 to 1

• Reflexes – Brisk knee jerks and ankle jerks with ankle clonus

• Plantars extensors

• Upper limbs normal


• Sensory:

• All modalities of sensation diminished below the umbilical level

• Definite upper level

• Band of hyperaesthesia at the level

• Abdominal reflexes - absent


• Where ?

• What ?

Case 2:55 year old diabetic

• Tingling & numbness both lower limbs X 2M

• Tingling & numbness both upper limbs X 1M

• Weakness in both lower limbs X 1 month

• What is the lesion?

• Where is the lesion?


• Control has been poor

• Has been having indigestion

• He is a strict vegetarian


• Vitals normal

• Pallor

• Hypovitaminosis

• Mild pitting edema

• Trophic ulcers on feet

Case 2:55 year old diabeticSensory: Glove and Stocking distribution of sensory loss -Pain, Temp,

touch, proprioception and vibration (variable levels)

Motor system: LL• Bulk & Tone – equal on both sides• Power -grade IV in lower limbs• Ankle Jerks- absent• Knee Jerks –normalUL

Normal


• What if she had additional weakness and stiffness in lower limbs with bladder complaints of frequency and incontinence?


And-

• Bulk – equal on both sides

• Tone increased in thigh muscles

• Grade IV weakness in both lower limbs

• Ankle jerks absent

• Knee Jerks brisk with clonus

• Plantars extensors

• Bladder incontinence – empty bladder

Diagnosis


• Myelopathy

• Diabetes and Nutritional etiology

Health & Medicine

Approach to a case of motor and sensory disorders