Spinal Dysraphism Presenting asAcro-Osteolysis: Report of Four Cases

Gomathy Sethuraman, M.D.,* Sanjeev Handa, M.D.,* Paramjeet Singh, M.D.,†Debabrata Ghosh, M.D.,‡ and Bhushan Kumar, M.D.*

Departments of *Dermatology, Venereology, and Leprology, †Radiodiagnosis and Imaging, and ‡Pediatrics,Postgraduate Institute of Medical Education and Research, Chandigarh, India

Abstract: The acro-osteolyses are a heterogeneous group of disorderscharacterized by bone resorption. The disorder may occur as familial,idiopathic, or secondary to vascular, inflammatory, or neurologic condi-tions. Acro-osteolysis is rare in association with spinal dysraphism. It iseven rarer for it to be the presenting symptom in spinal dysraphism. Wereport here four patients in whom the diagnosis of spinal dysraphism wasestablished while investigating for the various causes of acro-osteolysis.All four patients presented with trophic changes and acro-osteolysis. Hy-perhidrosis in the affected limb was seen in three patients. One patienthad leg pain, the others had no sensory or motor deficits. Magnetic reso-nance imaging showed spinal dysraphism in all four patients.

Acro-osteolysis is the term used for a heterogeneousgroup of disorders characterized by progressive skeletalrarefaction leading to disappearance of the affectedbone(s). The process starts in the phalanges and gradu-ally involves the other acral bones (1,2). Four types ofacro-osteolysis have been described (1,3): familial, idio-pathic or nonfamilial, toxic (occupational), and second-ary to inflammatory, vascular, neurologic, or metabolicdisorders.

Spinal dysraphism encompasses all defects (open andclosed) associated with a failure of closure of the poste-rior neural arch. Developmental errors may occur earlyin fetal life, leading to a variety of spinal defects. Thesedefects include spina bifida aperta (when intraspinal softtissue protrudes through the defect, e.g., meningocele,myelomeningocele) and spina bifida occulta (4,5). Acro-osteolysis is rarely associated with spinal dysraphism.We report here four cases of spinal dysraphism present-ing as acro-osteolysis.

CASE REPORTS

Patient 1

A 14-year-old girl had a 3-year history of hyperhidrosisand recurrent episodes of spontaneous blistering and ul-ceration of the left foot. Physical examination revealedgross deformity of the left foot. The great toe was short-ened and its terminal phalanx was lost, while the othertoes were grossly mutilated. A 2.5 cm diameter ulcercovered with hypertrophic granulation tissue and foul-smelling discharge was present over the third and fourthmetatarsal heads (Fig. 1). The plantar arch was obliter-ated. The right foot was normal and physical examina-tion revealed no other abnormalities or neurologic defi-cit. Roentgenogram of the left foot showed completeresorption of the phalanges involving the great toe andsecond and third toes with associated soft tissue irregu-larity and swelling. Roentgenogram of the lumbosacralspine (LS) showed spina bifida from L3 to L5. Magnetic

Address correspondence to G. Sethuraman, M.D., #17, MeenakahiNagar, Madurai – 625018, Tamil Nadu, India.

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resonance imaging (MRI) revealed a low-lying cordalong with diastematomyelia and focal syringomyelia(Fig. 2). A sweat test showed marked hyperhidrosis ofthe left foot (Fig. 3).

Patient 2

A 6-year-old boy had spontaneous blistering and ulcer-ation of the left great toe for the last 2 years. He also hadhyperhidrosis on the affected limb. Physical examinationrevealed the absence of the left great toe, slight mutila-tion of other toes of the left foot (Fig. 4), and obliterationof the plantar arch. The right foot was normal, as was thegeneral examination. Roentgenogram of the LS spineshowed absent spinous processes from L2 to L5. MRIdemonstrated diastematomyelia and a low-lying cord

Figure 1. Patient 1. Grossly mutilated left foot with anulcer present over the third and fourth metatarsal heads.

Figure 2. Patient 1. T1-weighted MRI shows (A) a split cord with diastematomyelic bar at the L2 level, and (B) a low-lyingcord up to L5 and a syrinx at the D12–L1 level.

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(Fig. 5). A sweat test revealed marked hyperhidrosis ofthe left foot.

Patient 3

A 32-year-old woman had a patch of hypertrichosis overthe lumbosacral region since birth and deformity of the

left foot since early childhood. She also had pain in theleft leg. Clinical examination revealed a partially de-formed left foot and a greatly mutilated great toe. Therewas an ulcer about 0.5 cm in diameter over the mutilatedgreat toe, and the plantar arch was obliterated. Therewere no other systemic abnormalities. Roentgenogram ofthe LS spine showed lumbosacral spina bifida. MRIshowed a low-lying cord tethered to a lipoma. A syrinxwas also noted at the D12–L1 level.

Patient 4

A 25-year-old woman presented with mutilation of herright great toe since the age of 5 years. She also hadhyperhidrosis on the right foot for the last 10 years. Shedid not have any other neurologic symptoms. Physicalexamination revealed shortening of the right great toeand swelling of the third toe. The plantar arch was oblit-erated. MRI showed a low-lying cord up to the L4 level.

The relevant clinical and MRI findings of all fourpatients are summarized in Table 1.

DISCUSSION

Spinal dysraphism refers to improper or inadequate fu-sion of the midline structures of the embryonal tissues inthe dorsal median region of the developing embryo. Thestructures involved may be neural, mesodermal or cuta-neous derivatives of the embryonal tissues. The mostcommon defects in spinal dysraphism are spina bifidacystica or aperta and spina bifida occulta (4).

Spina bifida occulta is not associated with protrusionof intraspinal structures through the vertebral defect, butthere is an associated spinal defect [e.g., diastematomy-elia (septate cord), tethered cord syndrome (low-lyingcord), and/or intraspinal neoplasm] (4,5). It affects5–17% of the population (6,7). Diastematomyelia refersto congenital splitting of a part of the spinal cord by abony, fibrous, or cartilaginous spur, which often extends

Figure 3. Patient 1. Sweat test shows hyperhidrosis onthe left side.

Figure 4. Patient 2. Absence of the left great toe.

Figure 5. Patient 2. T1-weighted MRI shows (A) diastematomyelia, and (B) a low-lying cord up to the L4–L5 levels.

Sethuraman et al: Spinal Dysraphism Presenting as Acro-Osteolysis99

directly across the spinal canal in the anteroposteriordirection. The conus medullaris lies well below its nor-mal level, tethered by the filum terminale. Vertebralgrowth proceeds more rapidly than the growth of thespinal cord, posing the risk of progressive neurologicdeficits. Tethered cord syndrome may occur without as-sociated diastematomyelia. There may be associated syr-inx or various neoplasms (5,8).

Spinal dysraphism usually manifests in childhood. Itpresents with a variety of signs and symptoms and theseare summarized in Table 2. Cutaneous findings are oftenthe initial markers. The various congenital cutaneous

markers include hypertrichosis, hemangiomas, port-winestain, dermal sinuses/dimples, aplasia cutis, hyperpig-mentation, hypopigmentation, acrochordon, and lipoma(4,9,10). In this report, only one adult patient had a cu-taneous lesion (hypertrichosis).

Neurologic manifestations of spinal dysraphism inchildren significantly differ from those in adults. Adultsgenerally suffer from excruciating and unrelenting painin the legs, groin, and perineum, while children seldomcomplain of pain, and when it is present, pain is localizedto the lower back (11,12). In this series, only one adultpatient reported pain in the leg. In children, motor defi-cits manifest as walking difficulties, gait abnormalities,and regression in gait training. Adults commonly presentwith frank weakness (11,12). None of our four patientshad either muscular paralysis or weakness.

The most common foot deformities in children withsymptomatic spinal dysraphism are progressive cavovarus and talipes. Other deformities include broad, short-ened contour, exaggeration of the horizontal and verticalarches, and contracture of the toes (6,8). In this report, allfour patients had obliteration of the plantar arch second-ary to acro-osteolysis.

Trophic changes of the lower extremities secondary tosympathetic denervation are seen occasionally in chil-dren, and these include smooth, shiny skin, hair loss, nailchanges, nonhealing ulcers in the toes, and acro-osteolysis (8). In our series, all four patients had trophicchanges. Less common dysautonomic symptoms of spi-nal dysraphism are bladder and bowel dysfunction(4,13). Disturbances of sweating are rarely seen in spinaldysraphism. Generally a decrease in or loss of sweatingoccurs below the level of partial spinal cord lesions, as in

TABLE 2. Clinical Spectrum of Spinal Dysraphism

Sensory motor deficitsDelayed motor milestones, frank weakness, muscle

wasting, hypo or areflexia (LMN involvement)Long tract signs (common in adults)Pain

Foot deformitiesProgressive talipesHammer toesExacerbation of horizontal or vertical archesEquinus, calcaneus, varus, and valgus

Spinal deformitiesProgressive scoliosisKyphosis

Trophic changesSpontaneous blistering, nonhealing ulcersRecurrent osteomyelitis and spontaneous amputation of

the toesAcro-osteolysis

Urologic problemsUrinary frequencyIncontinenceEnuresisHydronephrosis

TABLE 1. Clinical and Radiologic Features in our Four Patients

PatientAge(years) Sex

Age atOnset(years)

Autonomic Disturbances

TrophicChanges Acro-osteolysis

SweatingDisturbances

1. 14 Female 11 + + Hyperhidrosis2. 6 Male 4 + + Hyperhidrosis3. 32 Female 5 + + –4. 25 Female 5 + + Hyperhidrosis

TABLE 1. Continued

Patient

SensoryMotorDeficits

PlantarArch

CutaneousLesion

MRI Findings

Low-lyingCord Syringomyelia Diastematomyelia

1. – Obliterated – Up to L5 + (D12–L1) +2. – Obliterated – Up to L4–L5 – +3. Pain Obliterated Hairy patch Up to L4–L5 + (D12–L1) –4. – Obliterated – Up to L3–L4 – –

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spinal dysraphism. Excessive sweating (hyperhidrosis)may also occur, sometimes spontaneously and some-times as a reflex. This could probably be attributed to thelocal reflex functions of the spinal cord isolated fromcerebral control (14). Strikingly, three of our patients hadthis unusual feature of hyperhidrosis, which has not beenreported in other series (4,6,10–13).

In summary, the clinical presentation of spinal dysra-phism is variable depending on the location and extent ofthe underlying developmental defects as well as the de-velopment of secondary changes. Any patient with uni-lateral or asymmetrical acro-osteolysis in a lower limbshould be investigated for spinal dysraphism. Althoughhyperhidrosis is not a unique feature of spinal dysra-phism, presence of this sign in association with unilateralacro-osteolysis may be indicative of an underlying spinalcord abnormality. MRI seems to be the best radiologicstudy to demonstrate the various spinal cord anomalies.

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