Using the Syndromes Approach in Evaluating Patients Suspected of Having

Neurologic Dysfunction

• Dr. Jay McDonnell• Eddress: drjaymcd@gmail.com

410.224.0121

Decision making in Neurologic Diagnosis

• Is it neurologic?• Is it intracranial, spinal cord or peripheral?• With history, PE and NE localization, what

are the possible diagnoses? (algorithms)• What are most efficient methods for

determining the most likely diagnoses?

Intracranial signs

• Seizures/convulsions• Altered mental status• Head tilt/circling/nystagmus• Intention tremor/dysmetria• Blindness

Intracranial Localization

• Cerebral cortex• Diencephalic• Brain stem• Vestibular-

– central or peripheral

• Cerebellar

Cerebral cortex

• Alterations in behavior/mental status• Seizures, convulsions• Blindness with normal pupils• Decreased facial sensation• Mild hemiparesis with postural reaction

deficits

Diencephalon

• Hypothalamic signs• Ipsilateral CN III, IV, VI• Alterations in behavior/mental status• Subtle hemi or tetraparesis with postural

reaction deficit.

Brain stem

• Obvious hemi or tetraparesis• Ipsilateral CN signs (III-XII)• Alterations in behavior/mental status

Vestibular

• Falling, rolling, head tilt, circling, abnormalnystagmus, strabismus and asymmetricataxia

• Central vs. peripheral

Vestibular disease

Nystagmus Horizontal or Rotary Horizontal, rotary or vertical

Motor or postural reactions No deficits Deficits possible

Cranial nerves Facial nerve (VII) Any possible

Horner’s syndrome Possible Absent

Cerebellar signs Absent PossibleMentation Disoriented/anxious but

otherwise normal Possible

Peripheral Central

Cerebellar• Ataxia• Dysmetria• Wide based stance• Intention tremor• Cerebellar nystagmus• Absent menace with normal vision• No Weakness

Case example: Bourbon:

12 yoMN

LabPei

Spinal cord localization

• Cervical• Cervicothoracic• Thoracolumbar• Lumbosacral• Pelvic plexus

Tetraparesis

lWhen tetraparesis is unaccompanied by signs associated with disease above the foramen magnum - brain disease is less likely.lBrainstem lesions may be accompanied by cerebellar and or cranial nerve signs.

C1-T2 general features

•Root signature

C5-T2 general features

•Depressed/absent panniculus reflex– C8-T1

C5-T2 general features

• Horner’s syndrome - T1-2

Paraparesis/Paraplegia

• Pelvic limb motor dysfunction.• Thoracic limbs normal.• Neurolocalization caudal to T2.

T3-L3 thoracolumbar

• Spinal cord lesion between the cervical and lumbarintumescences.

• Normal mentation, cranial nerves and thoracic limbs• Varies:

– Weakness in pelvic limbs - scraping nails and paws, crossingand knuckling – paraparesis

– Paralyzed – no motor in pelvic limbs

T3-L3 thoracolumbar

• Muscle tone - typically increased.• Postural reactions are slow to absent only in the

pelvic limbs– Knuckling-placing– Hopping– Hemistand, hemiwalk

T3-L3 thoracolumbar

• Reflexes - spastic– Withdrawal reflexes are intact (normal)– Patellar reflexes are normal to increased

• Muscle atrophy is mild, generalized and due todisuse.

• Muscle fasciculations are not a typical component

T3-L3 thoracolumbar

• Sensation affected - dependent onseverity of the lesion– loss of superficial pain– loss of deep pain

Loss of function IVDD-prognosis

• Conscious proprioception• Voluntary motor• Superficial pain and • bladder control• Deep pain

T3-L3 thoracolumbar

• Cutaneous trunci –• Panniculus

• Hyperesthesia• Hypesthesia

T3-L3 thoracolumbar

T3-L3 thoracolumbar

• Urinary incontinence - UMN bladder– difficult to express bladder– good detrusor tone, overflow incontinence– urine retention– perineal & bulbocavernous reflex intact– sensation to perineum and tail intact

UMN vs LMN signsT3-L3 vs L4-S2 localization

• Motor function• Muscle tone• Reflexes

• Muscle atrophy• Sensory signs• Fasciculations

L4-S2 Lumbosacral

•Spinal cord lesion within thelumbar intumescence•Think of function of nerves inthis swelling.

– Femoral nerve– Sciatic nerve– Pudendal nerve

L4-S2 Lumbosacral

• Normal mentation, cranialnerves and thoracic limbs

• Depending on the location of thelesion weakness in pelvic limbsmay be minor or quite severe -function

L4-S2 Lumbosacral

• Muscle tone is decreased.– Pelvic limbs only, tail and anus normal.– Pelvic limbs normal, tail and anal

sphincter flaccid.• Postural reactions are normal to slow

depending on location of lesion

L4-S2 Lumbosacral

• Reflexes - dependent on location– Depressed pelvic limb reflexes– Normal reflexes with depressed

perineal and bulbocavernosus reflexes

– Sciatic release

L4-S2 Lumbosacral

• Muscle atrophy in pelvic limband hip muscles.– Segmental muscle atrophy

• Muscle fasciculation may bepresent.

L4-S2 Lumbosacral

• Sensation• panniculus• perineal sensation• tail sensation

L4-S2 Lumbosacral

• With involvement of S1-3 - LMN bladder– bladder easy to express, urinary incontinence– distended atonic bladder, dribbles constantly– perineal and bulbocavernous reflex decreased to

absent– sensation to perineum and tail may be decreased to

absent

UMN vs LMN signsT3-L3 vs L4-S2 localization

• Motor function• Muscle tone• Reflexes

• Muscle atrophy• Sensory signs• Fasciculations

• Goals for lecture–Using a syndromes matrix to help

the veterinarian approachneurological patients