None John Engstrom, MD DP-History DP-History LBP to R leg since - - PowerPoint PPT Presentation

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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RAIN 2015: Challenging Cases A 48 yo woman with LBP to right leg and burning feet

John Engstrom, MD

Disclosures

None

DP-History

• LBP to R leg since 2009; Rx lumbar surg
• Constant burning pins and needles over

soles of her feet-constant x 6-10 years; better after spine surgery

• Prior EMG sural NAPs R 5 L 6 microvolts
• Nortriptyline (suicidal ideation) and

gabapentin (leg swelling) unsuccessful

DP-History

• Lyrica 100 mg tid; oxycodone 10 mg prn
• Simvastatin/levothyroxine
• PMH-HTN, depression, asthma, headache,

hyperlipidemia, hypothyroidism

• Part-time social services eligibility worker

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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DP-Examination

• BP 157/90; Afebrile; P70, reg; Wt 267 lbs
• Mental status and cranial nerves-normal
• Motor-normal bulk, tone, coordination, gait
• Power-nl foot plantar flexion, eversion, and

dorsiflexion; great toe dorsiflexion

• Reflexes-2+, including ankle reflexes
• Sens-LT/pos nl; Pin decr mid-calves bilat

Q1-What is your working diagnosis based on the presented exam findings?

• A. Distal symmetric polyneuropathy
• B. Erythromelalgia
• C. Distal symmetric small fiber

polyneuropathy

• D. Burning feet syndrome
• E. Syringomyelia

Distal symmetric polyn... Erythromelalgia Distal symmetric small fi... Burning feet syndrome Syringomyelia

13% 3% 4% 12% 68%

DSFPN-unmyelinated and thinly myelinated sensory and autonomic fibers

• Idiopathic
• Glucose intol or Rx-induced; HgBA1c, hx
• Alcohol abuse; hx…occult hx
• HIV; HIV Antibody
• MGUS-SPEP/IEP

Distal Small Fiber Polyneuropathy

• Na chan mut-Nav 1.7-inher erythromelalgia
• Big 3: Vasculitis, Sarcoid, Lymphoma
• Hepatitis
• Hereditary-AIP, Fabry’s Dz, HSAN1
• Meds-discuss alternative medications
• Anti-retrovirals (ddC,ddI,d4T);
• Leflunomide, chloramphenicol

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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DP-More History

• Her primary care physician told her the

symptoms are probably from diabetes

• Patient: “How can I have both burning feet

+ decreased sensation to pin? Am I crazy?”

• Your credibility is on the line

Q2-Which one of the following statements is true?

• A. The decreased pin sensation probably

reflects loss of sensory neurons

• B. The preservation of some pin sensation

reflects the preserved function of sensory neurons

• C. The burning sensation reflects the

dysfunction of sensory neurons

• D. All of the above

T h e d e c r e a s e d p i n s e n s a t . . . T h e p r e s e r v a t i

• n
• f

s

• m

e . . . h e b u r n i n g s e n s a t i

• n

r e f . . . A l l

• f

t h e a b

• v

e

0% 92% 7% 1%

Q3-What is most impt to add to her neurologic exam?

A. Funduscopic exam B. Flexion of the toes C. Repeat ankle reflexes D. Her exam is complete

F u n d u s c

• p

i c e x a m F l e x i

• n
• f

t h e t

• e

s R e p e a t a n k l e r e f l e x e s H e r e x a m i s c

• m

p l e t e

58% 9% 11% 23%

The Weak Patient: Key Evaluation Features

Power Reflexes Sensation AHC Patchy

• r normal

normal Nerve Root (i.e. - Radiculopathy)

• r normal

*

• r normal

Nerve-Axonal (i.e. – DSPN) distal distal distal Nerve - Demyelination (i.e. - GBS) diffuse diffuse patchy/ normal NMJ (i.e. -Myasthenia) proximal normal normal (+/- bulbar) Muscle(i.e. - Polymyositis) proximal normal normal * - in distribution of affected root

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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DP-Exam and EMG

• Toe flexors are 5 in power bilaterally
• Sens nerve conduction studies (microvolts)

– Sural R 4; L 7 – Superficial peroneal R 4; L no response

• Tibial and peroneal motor NCS normal
• Needle EMG of distal leg muscles normal

DP-Labs

• CRP 35.7 (< 6.3 nl); ESR 47
• SSA/B negative; cANCA/pANCA negative
• SPEP/IEP normal
• RF 47 (mildly inc) CH50 58.1 (elevated),
• Cr 1.17 (eGFR 49); UA esterase +
• ALT 19, AST 23, Alk phos 85, T bili 0.7
• ANA + > 640, mixed; anti-DS DNA neg
• Hep B/C serologies negative

Q4-Which statement is true?

• A. The patient has systemic vasculitis
• B. The patient has lupus
• C. The patient has rheumatoid

arthritis

• D. The labs need to be correlated

with other clinical symptoms and signs

T h e p a t i e n t h a s s y s t e m i c . . . T h e p a t i e n t h a s l u p u s T h e p a t i e n t h a s r h e u m a t

• .

. T h e l a b s n e e d t

• b

e c

• r

r . . .

10% 85% 3% 2%

DP-More History/Lab

• No arthritis, photosensitive skin rash,

Raynaud’s phenomenon

• No dry eyes/mouth; no asthma, sinusitis
• No genital ulcers; 1 episode of oral apthous

ulcers in last year

• Cryoglobulins negative
• Polyarthralgia (knees, shoulders, ankles)
• A diagnostic test was performed

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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DP-Right Sural Nerve Bx Results

• Perivascular/intramural inflam consisting of

plasma cells and CD3-positive lymphocytes

• Inflammatory infiltrate invades walls of

multiple arterioles

• No fibrinoid necrosis seen
• Immunohistochemical stains for plasma cell

neoplasm negative

• Diagnosis: Small vessel vasculitis

Q5-What is most common pattern seen on neuro exam in vasculitic polyneuropathy?

• A. Mononeuropathy multiplex
• B. Distal symmetric polyneuropathy
• C. Mononeuropathy
• D. Demyelinating polyneuropathy

M

• n
• n

e u r

• p

a t h y m u l t i p l e x D i s t a l s y m m e t r i c p

• l

y n e . . . M

• n
• n

e u r

• p

a t h y D e m y e l i n a t i n g p

• l

y n e u r . . .

63% 2% 5% 30%

Nonsystemic Vasculitic Neuropathy

• ¼ of vasculitic neuropathy
• Fever, weight loss uncommon
• Indolent, not fatal if untreated
• May treat with steroids +/- cytotoxic drug
• Average duration of symptoms 11 years!
• 10% go on to systemic vasculitis

John W. Engstrom, M.D. Difficult Diangnosis - RAIN 2008 February 15, 2008

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DP-Course

• Rx with prednisone (60mg/d initially with

taper to 10 mg/d now)

• Azathioprine (200 mg/d) x 2 months
• Pain with neuropathy better; cont Lyrica
• Prednisone keeps her awake; on taper
• CRP 14.5
• Nonsystemic vasculitic neuropathy

– Yes: indolent course over 6+ years! – No: arthralgias; renal insuff; serologic markers

Take-Home Points

• Vasculitic neuropathy often presents with

an apparent symmetric pattern on neuro exam, but NCVs reveal asymmetries

• Routine screen for treatable causes of

polyneurop should include CRP and ESR

• Search for disorders assoc with vasculitis
• Nerve biopsy characterizes the nature of the

infiltrate and type of vessels affected