Paradoxical stroke in patient with ASD – 7/9/18

Today, Joe presented the case of a young woman presenting with acute onset of L sided weakness, found to have a paradoxical stroke due to ASD!

Clinical Pearls

  • Paradoxical stroke is a diagnosis of exclusion
  • Atrial septal defects (ASDs) have been associated with cryptogenic stroke (stroke of unknown etiology).  An embolic source is often not identified.
  • Ostium secundum is the most common type of ASD (>70% of cases)
  • Indications for ASD closure include the following
    • Symptomatic patient (DOE, platypnea-orthodeoxia)
    • R sided cardiac chamber enlargement
    • Left to right shunt >1.7:1
    • Before pacemaker or device placement
    • After a stroke
  • What about PFOs and cryptogenic stroke?
    • In the past, the recommendation was not to close them.  However, the 2017 CLOSE and REDUCE trials (as well as the 2013 RESPECT trial) showed that closure of PFO reduces the risk of a second stroke compared with medical therapy alone.  Thus, the latest ACC recommendation is to close PFOs after stroke!

Etiologies of stroke in a young adult:

  1. Hypercoagulable state
    • Inherited disorders
      • Protein C/S deficiency
      • Factor V Leiden
      • Prothrombin 20210 mutation
      • High homocysteine levels
      • Sickle Cell Disease
    • Acquired disorders
      • Pregnancy
      • OCPs
      • Estrogen hormone replacement therapy
      • Malignancy
      • APLS
      • DIC
  2. Vasculopathy
    • Noninflammatory
      • Dissection
      • Trauma
      • Connective Tissue Disease
      • Fibromuscular dysplasia
      • Migraine with aura
    • Inflammatory
      • Vasculitis
        • Large vessel: Takayasu, GCA
        • Small to medium: Kawasaki, PAN
      • Secondary vasculitis
        • Bacterial meningitis
        • HIV
        • Varicella
        • Syphilis
        • TB
        • Fungi (esp cocci)
    • Malformations
      • AVMs –> hemorrhagic
      • Aneurysms –> hemorrhagic
    • Venous
      • Cerebral venous sinus thrombosis
    • Other
      • Moyamoya
  3. Metabolic
    • Vessel injury
      • CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)
      • Fabry
      • Homocystinuria
    • Pure metabolic
      • MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes)
      • Organic acid disorders
  4. Drugs
    • Cocaine
    • Meth
  5. Cardiac
    • Congenital
    • Rheumatic valve disease
    • Mitral Valve Prolapse
    • PFO
    • ASD
    • Endocarditis with septic emboli
    • Atrial myxomas
    • Fibroelastoma
    • Arrhythmias
    • Cardiac surgery

Atrial Septal Defects

  • Secundum is seen in 75% of cases
  • Exam findings:
    • Fixed split S2
    • Parasternal impulse
    • Mid-systolic mumur at LSB (can be mid-diastolic also)
    • EKG with RV strain and partial RBBB
  • Indications for closure:
    • After stroke
    • Symptomatic patient
      • DOE
      • Platypnea-orthodeoxia syndrome
    • R sided cardiac chamber enlargement
    • L to R shunt > 1.7:1 (based on TTE findings)
    • Before pacemaker/device placement


Subacute combined degeneration of spinal cord – 7/3/18

Brooke presented a fascinating case of a middle aged man with history of substance use disorder presenting with acute on chronic back pain, weakness, and urinary retention, found to have subacute combined degeneration of the spinal cord from vitamin B12 deficiency due to using >100 canisters of nitrous oxide daily!

Clinical Pearls

  • Vitamin B12 deficiency can lead to degeneration of the dorsal and lateral white matter of the spinal cord ⇒ subacute combined progressive weakness, sensory ataxia, paresthesias, spasticity, paraplegia, and incontinence.
  • Nitrous oxide use (“Whippits”) inactivates vitamin B12 in the blood, rendering the body effectively vitamin B12 deficient.
    • In patients with history of N2O abuse, always check MMA levels with vitamin B12 since the latter is not a marker of functional B12 availability.
    • Treatment involves high dose B12 supplementation and stopping Whippits!

Differential for myelopathies:

  • Syringomyelia ⇒ cavitation of central spinal cord resulting in LMN symptoms with sensory changes
  • Inflammatory
    • Transverse myelitis
      • Viral prodrome
      • Usually associated with MS or autoimmune diseases
      • Typically involves the thoracic cord
      • Symptoms develop over hours
    • Sarcoid
      • Mimics transverse myelitis or tumor
    • Praneoplastic syndromes
  • Infectious
    • Epidural abscess
    • Acute viral myelitis
      • Enteroviruses (coxsackie, polio), flaviviruses (WNV, Japaneses encephalitis)
      • CMV, VZV, HSV, HCV, EBV (these viruses are less clearly associated)
    • AIDS myelopathy
    • HTLV-1 myelopathy
    • Syphilis
      • Tabes dorsalis (affects dorsal columns)
    • TB
    • Parasites
      • Schistosoma, cysticercosis
  • Vascular
    • Spinal cord infarction
    • Vascular malformations
    • Spinal epidural hematoma
  • Toxic/metabolic disorders
    • Subacute combined degeneration of spinal cord ⇒ degeneration of dorsal and lateral white matter (think Whippits and B12 deficiency!)
    • Copper deficiency myeloneuropathy
    • Radiation induced myelopathy
    • Hepatic myelopathy (purely motor symptoms, lower extremities predominant, in patients with ESLD)
    • Decompression sickness myelopathy (in deep sea divers)
  • Neoplasms
  • Degenerative conditions
    • ALS
  • Demyelinating diseases
    • MS

Inhalant Abuse:

Side effects are broad and include

  • CNS effects
  • CV: arrhythmias, myocarditis, MI “sudden sniffing death”
  • Pulmonary: hypoxia, pneumonitis, hemorrhagic pulmonary edema, PTX from pressurized tanks
  • GI: n/v, abdominal cramps, anorexia, hepatotoxicity
  • Renal effects: AGMA (with volatile substances), urinary calculi, nephrolithiasis
  • Hematologic: aplastic anemia, malignancy (leukemia, lymphoma, MM)
  • Derm: “Glue-sniffer’s rash”. Eczematoid dermatitis with erythema, inflammatory changes, and pruritis in the perioral area and midface
  • MSK: rhabdo