Mixed CNS / PNS Syndromes & Neurodevelopmental Disorders

Question 1

Thiamine deficiency neural syndromes
Main 2
Age
Risk factors

Answer 1

• Wernicke’s encephalopathy – acute reversible triad of confusion, ophthalmoparesis, and gait ataxia.
• Korsakoff’s dementia / psychosis – chronic irreversible dementia w/ anterograde amnesia and confabulation. May or may not have polyneuropathy.
• Most common in middle aged. More men than women.
• Risk factors – chronic heavy ethanol consumption, malnutrition, bariatric surgery, or AIDS.

Question 2

Neuroborreliosis
Cause
Onset
Syndromes
Age

Answer 2

Borrelia burgdorferi (spirochete that causes Lyme disease)
Subacute
Most commonly causes aseptic meningitis or BILATERAL facial neuropathy.
Mainly affects young adults / middle aged.

Question 3

B12 deficiency neural syndromes
Sxs
Onset
Age
Risk factors
Additional features

Answer 3

Polyneuropathy, combined degeneration of SC (meaning both posterior columns and corticospinal tracts), or dementia. Both UMN and LMN signs.
Gradual
Mainly affects elderly: Intrinsic factor production and binding decreases w/ age.
•Risk factors – vegetarian diet, malnutrition, bariatric surgery, meds that suppress gastric acid secretion, or ileal dysfunction.
•Additional features include anemia, depression, and GLOSSITIS (tongue inflammation)

Question 4

Alcohol neural syndromes
Description
Onset
Population

Answer 4

Diffuse cerebral / cerebellar dysfunction from intoxication or withdawal. May involve gradual polyneuropathy, cerebellar atrophy (especially vermis), or dementia.
Gradual
Most commonly affects the middle aged. Men more than women.

Question 5

HIV neural syndromes
Signs
Population
Pathology

Answer 5

May have combined posterior columns and corticospinal dysfunction in SC. May have both UMN and LMN signs.
•Rapid neural syndromes may occur during seroconversion (initial stage of infection) such as aseptic meningitis or polyradiculoneuropathy.
•Opportunistic infections that affect the NS include CMV encephalitis, cryptococcal meningitis, or tuberculous meningitis.
•Abscess from Toxoplasma gondii (protozoan) or lymphoma may cause focal brain syndromes
•Mainly affects young adults / middle aged. More men.
•Pathology - cortex ay show infiltration of giant cells. Direct neural cell injury is slow, but infection / neoplasm may be fast.

Question 6

Which 2 syndromes look almost identical?

Answer 6

HIV and B12 deficiency

Question 7

Which 3 syndromes cause both UMN and LMN signs?

Answer 7

HIV, B12, and ALS

Question 8

Amyotrophic lateral sclerosis

Answer 8

Both UMN and LMN loss. May involve progressive executive dysfunction or general dementia.
Most common in middle aged / elderly. More men.
•Risk factors – smoking, family hx of ALS
•Pathology – SC atrophy, may see diffuse atrophy of cerebral cortex (especially PFC).

Question 9

1 year developmental milestones (4)

Answer 9

Walking (gross motor), pincer rasp (fine motor), 1-2 words, waving (social).

Question 10

Chiari malformation

Risk factor

Answer 10

Congential small posterior cranial fossa → cerebral tissue to be inferior to foramen magnum. Usually asymptomatic, but may cause postural headaches (worsen w/ prolonged standing), dysfunction of posterior fossa structures (cerebellum / CNs), or noncommunicating hydrocephalus.
•Risk factor – neural tube defect

Question 11

Cerebral palsy
Description
Risk factors
Spastic diparesis / quadriparesis / hemiparesis

Answer 11

Static CNS motor dysfunction (mainly UMNs). Knees do not flex, heels do not touch ground, legs cross in front of each other w/ each step (scissoring gait). Usually don’t see sensory problems. May involve cognitive developmental delay / ID. Periventricular abnormalities → leg UMN problems. Missing white matter
•Risk factors – preterm birth, intrauterine encephalitis / cerebral infarction / hemorrhage / neurotoxin exposure.
•Spastic diparesis – motor deficits / spasticity of legs more than arms. May involve absent / abnormal white matter adjeacent to lateral ventricles (called periventricular leukomalacia). Mainly seen in premies due to active germinal matrix being vulnerable to ischemia.
•Spastic quadriparesis – motor deficits / spasticity that is similar in arms and legs. May involve absent / abnormal diffuse white and gray matter caused by global ischemia. Usually seen in full-term infants b/c germinal matrix is less active, so UMNs are vulnerable.
•Spastic hemiparesis – unilateral motor deficits / spasticity. May involve absent / abnormal tissue of unilateral white / gray matter caused by ischemia.

Question 12

Problems that may arise w/ spina bifida

Answer 12

Myelopathy at affected level. May also include scoliosis, joint contractures, hydrocephalus, cognitive deficits, epilepsy.

Question 13

Spinal meningocele vs myelomeningocele

Answer 13

• Spinal meningocele – herniation of meninges but not neural structures.
• Myelomeningocele – herniation of both meninges and neural structures. Incontinence is a common problem.
• Both meningoceles may be associated w/ Chiari malformation or hydrocephalus

Question 14

Anencephaly vs encephalocele (2 types) vs craniorachischisis

Answer 14

• Anencephaly – most common cranial neural tube defect. Cerebrum and skull fails to form, but brainstem or SC functions may be present.
• Encephalocele – cranial defect w/ herniation of meningies alone (cranial meningocele) or meninges and some brain tissue (encephalomeningocele)
• Craniorachischisis – no functional CNS tissue or overlying bones / tissues. Risk factor is low maternal folate during neurulation.