Tonic pupil, areflexia, and segmental anhidrosis: two additional cases of Ross syndrome and review of the literature

A guide to identify cervical autonomic dysfunctions (and associated conditions) in patients with musculoskeletal disorders in physical therapy practice

BACKGROUND

Differential diagnosis is a hot topic in physical therapy, especially for those working in a direct access setting dealing with neck pain and its associated disorders. All international guidelines agree in recommending to first rule out non-musculoskeletal pathologies as the cause of signs and symptoms in the patient. Although the autonomic nervous system (ANS) has a crucial role and is also involved in pain conditions, coverage of it in neuroscience textbooks and educational programmes is limited and most healthcare professionals are unfamiliar with it. Although autonomic conditions are benign in nature, they are clinically of great importance as they may be a 'red flag' warning of an injury along the sympathetic pathway. Therefore, sound knowledge of the ANS system is essential for clinicians.

OBJECTIVE

To develop physical therapists' knowledge of and confidence in understanding cervical ANS function and dysfunction, thus enhancing clinical reasoning skills and the pattern recognition process, and performing and interpreting objective examinations.

METHODS

This master class provides an introductory guide and essential knowledge to facilitate clinicians to understand cervical autonomic dysfunctions and their clinical evaluation. The optimal referral method is also handled.

CONCLUSIONS

Gaining knowledge and understanding of the ANS, its function, its dysfunction, and the related clinical manifestations is likely to lead to a decision-making process driven by 'science and conscience'. This will empower physical therapists to be aware of subtle clues that may be offered by patients during the interview and history intake leading to the appropriate physical examination and triage.

Clinical presentation and autonomic profile in Ross syndrome

BACKGROUND

Ross syndrome is a rare disorder characterized by tonic pupils, hyporeflexia, and segmental anhidrosis. We sought to characterize the clinical presentation, associated autoimmune disorders, and autonomic profile in patients with Ross syndrome to further elucidate its pathophysiology.

METHODS

We performed a retrospective chart review of all patients who underwent a thermoregulatory sweat test (TST) between 1998 and 2020 and had confirmation of the diagnosis of Ross syndrome by an autonomic disorders specialist. Standardized autonomic reflex testing was reviewed when available.

RESULTS

Twenty-six patients with Ross syndrome were identified. The most common initial reported manifestation was an abnormal segmental sweating response in 16 patients (described as hyperhidrosis in 12 patients and anhidrosis in 4 patients) while a tonic pupil was the initial manifestation in 10 patients. Other commonly reported symptoms included fatigue, chronic cough, and increased urinary frequency. An associated autoimmune disorder was identified in one patient. Positive autoantibodies were found in a minority of patients often with unclear clinical significance. Distributions of anhidrosis encountered were segmental (n = 15), widespread (n = 7), and global (n = 4). Well-circumscribed small areas of preserved sweating within areas of anhidrosis were observed in the majority of patients (88.5%). Anhidrosis progressed slowly over time and sudomotor dysfunction was predominantly (post)ganglionic. Cardiovagal and adrenergic functions were preserved in most patients.

CONCLUSIONS

The pattern of autonomic dysfunction in Ross syndrome is suggestive of a limited autonomic ganglioneuropathy. Sudomotor impairment is prominent and should be the focus of symptomatic management; however, clinicians should be aware of symptoms beyond the classic triad.

Sudomotor Dysfunction

Disorders of sudomotor function are common and diverse in their presentations. Hyperhidrosis or hypohidrosis in generalized or regional neuroanatomical patterns can provide clues to neurologic localization and inform neurologic diagnosis. Conditions that impair sudomotor function include small fiber peripheral neuropathy, sudomotor neuropathy, myelopathy, α-synucleinopathies, autoimmune autonomic ganglionopathy, antibody-mediated hyperexcitability syndromes, and a host of medications. Particularly relevant to neurologic practice is the detection of postganglionic sudomotor deficits as a diagnostic marker of small fiber neuropathies. Extensive anhidrosis is important to recognize, as it not only correlates with symptoms of heat intolerance but may also place the patient at risk for heat stroke when under conditions of heat stress. Methods for assessing sudomotor dysfunction include the thermoregulatory sweat test, the quantitative sudomotor axon reflex test, silicone impressions, and the sympathetic skin response.

Is Ross Syndrome a New Type of Synucleinopathy? A Brief Research Report

Ross syndrome (RS) is a rare peripheral autonomic system disorder characterized by tonic pupil, hyporeflexia, and segmental anhidrosis. Neuropathological studies show that RS results from the selective cholinergic nerve degeneration. However, the cause and underlying mechanisms are largely unknown. Here, we show α-synuclein accumulation in the autonomic nerve terminals in the lesser curvature of stomach of patients with RS. In addition, immunohistochemical findings demonstrate that a dominant degeneration of cholinergic fibers is exhibited in patients with RS, while main degeneration of adrenergic fibers is demonstrated in patients with pure autonomic failure in their gastrointestinal and urinary system. Our study suggests that RS belongs to α-synucleinopathies. Moreover, our findings indicate that adrenergic nerves and cholinergic nerves are not equally damaged in different types of pure autonomic dysfunctions.

[Clinical presentations of Ross syndrome have changed in their lateralities following the anteriotemporal lobectomy for refractory focal epilepsy]

We describe a 60-year-old woman with medically refractory left mesial temporal lobe epilepsy accompanied by Ross syndrome. The patient had a partial triad of Ross syndrome with hypohydrosis only on her right side (contralateral to the epileptic seizure focus), Adie's tonic pupil on the right, and areflexia while her seizures used to be medically refractory. However, her hypohidrosis and Adie's tonic pupil have completely changed in terms of laterality following nearly complete seizure freedom resutling from left temporal lobectomy. This unique change in laterality in Ross syndrome is most likely caused by remote effects of the near-absent epileptic acitivity, and it also may contribute to understanding the pathophysiological mechanism of Ross syndrome.

Ross syndrome with ana positivity: a clue to possible autoimmune origin and treatment with intravenous immunoglobulin

A 28-year-old serving soldier presented with patchy areas of absence of sweating and blurring of vision. On examination he was found to have segmental anhidrosis, right sided tonic pupil and absent ankle jerks. Investigations revealed ANA positivity with no other abnormalities. He was treated with Intravenous immunoglobulin. This case of Ross syndrome is reported for its rarity as well as a clue to its probable autoimmune origin and treatment option with intravenous immunoglobulins.

Disorders of the pupil

Pupil size is determined by the interaction of the parasympathetic and the sympathetic nervous system. The parasympathetic system conducts the light reaction with its major center in the dorsal midbrain. The sympathetic nervous system acts either directly on the dilator muscle (peripherally) or centrally by inhibiting the Edinger-Westphal nucleus. Psychosensory reactions are transmitted via the sympathetic system. The afferent input of the light reflex system in humans is characteristically wired, allowing a detailed analysis of a lesion of the afferent input. Even in humans a subgroup of ganglion cells containing melansopsin plays an important role as a light sensor for the pupillary system. To diagnose normal pupillary function, pupils need to be isocoric and react bilaterally equally to light. Anisocoria indicates a problem of the efferent pupillary pathway. Pupillary disorders may involve the afferent pathways (relative afferent pupillary defect) or the efferent pathways. Physiological anisocoria is a harmless condition that has to be distinguished from Horner's syndrome. In this case pharmacological testing with cocaine eye-drops is helpful. Disorders of the parasympathetic system will impair the light response. They include dorsal midbrain syndrome, third-nerve palsy, and tonic pupil. Tonic pupils are mainly idiopathic and do not need imaging. Disorders of the iris, including application of cholinergic agents, need also to be considered in impaired pupillary light reaction.

Ross syndrome associated with cytomegalovirus infection

We report a 40-year-old woman who developed Ross syndrome (impairment of sweating and thermoregulation, tonic pupils, and hyporeflexia) associated with cytomegalovirus (CMV) infection. Her serum CMV IgM and IgG antibody titer levels were elevated. Along with clinical improvement, a gradual decrease of her elevated CMV IgM antibody titer level was seen with a continued increase in her CMV IgG antibody titer level. The CMV IgM antibody titer was also positive in the cerebrospinal fluid.

Anhidrosis: A clue to an underlying autonomic disorder

We describe a patient with Ross syndrome who had the classic triad of segmental anhidrosis, tonic pupils and hyporeflexia. Dilute pilocarpine (0.1%) instillation in both eyes revealed parasympathetic denervation hypersensitivity. There was evidence of cardiac dysautonomia in the form of a decrease in heart rate variability with deep breathing and an abnormal Valsalva response. A thermoregulatory sweat test showed the presence of sweating in the right cheek, neck and upper one-third of the left arm and shoulder only. Sympathetic skin responses were absent in the affected segments of the upper limb. Ross syndrome is a degenerative disorder that progressively involves different fibre populations, starting with autonomic fibres and then involving the unmyelinated and myelinated sensory fibres. A careful clinical examination and simple bedside autonomic tests can confirm the diagnosis.

Ross syndrome, an entity included within the spectrum of partial disautonomic syndromes

Ross syndrome is a degenerative peripheral nervous system disorder defined by the following triad: unilateral or bilateral segmental anhidrosis, hyporeflexia of deep tendon reflexes and Adie's tonic pupils. The most disturbing symptom is segmental compensatory hyperhidrosis. It has only occasionally been reported in the dermatological literature. We present a 35-year-old woman with chronic hepatitis C who developed the characteristic triad of Ross syndrome within 1 month. The patient was otherwise healthy except for an aneurysm of the left medium brain artery not responsible for the syndrome.

Anhidrosis segmentaria asociada a pupila de Adie: un caso de síndrome de Ross incompleto

We present the case of a 43-year-old woman who presented with a localized area of anhidrosis on the upper left trunk and ipsilateral upper limb. It was associated with Adie's tonic pupil and an area of compensatory hyperhidrosis on the contralateral side. After 9 years of follow up, the alterations have remained stable. These alterations of the autonomous nervous system correspond to an incompletely expressed Ross syndrome.

Segmental Facial Anhidrosis and Tonic Pupils With Preserved Deep Tendon Reflexes: A Novel Autonomic Neuropathy

A 31-year-old woman had exertional right-sided hemifacial flushing and sweating. Examination demonstrated slightly dilated pupils with absent constriction to light and a tonic near response and redilatation, features consistent with Adie syndrome. Neurological examination was otherwise normal, including preservation of deep tendon reflexes. Magnetic resonance imaging of brain and spine were normal. The combination of unilateral loss of sudomotor and vasomotor activity without loss of ocular sympathetic innervation fulfills the diagnosis of Harlequin syndrome. The combination of Harlequin and Adie syndromes has been called Ross syndrome, but the preservation of deep tendon reflexes precludes a diagnosis of Ross syndrome in our patient. This previously undescribed variant adds further complexity to the spectrum of autonomic neuropathies.

Is Ross syndrome a dysautonomic disorder only? An electrophysiologic and histologic study

OBJECTIVE

To define the involvement of peripheral nerve fibers in Ross syndrome.

METHODS

Mechanical pain perception, tactile and thermal thresholds on hand, foot dorsum, thigh, median nerve orthodromic sensory conduction velocity (SCV) and motor conduction velocity (MCV), sural nerve antidromic SCV, peroneal nerve MCV, H-reflex, F-wave, median, tibial nerve somatosensory evoked potentials (SSEPs), perioral, hand CO(2) laser late (LEPs) and ultralate evoked potentials, sympathetic skin response (SSRs), cardiovascular, Minor sweat, silastic imprint, histamine, photopletysmographic and pupil pilocarpine tests, cutaneous innervation immunohistochemical techniques were studied in 3 patients with Ross syndrome.

RESULTS

Quantitative sensory testing showed altered results in patients 1 and 2, and patient 3 had a slight impairment of mechanical pain perception. Nerve conduction, except for a median nerve distal reduction of sensory conduction in patient 1, F-wave and SSEP findings were normal; H-reflex was absent at rest in all patients. Hand LEPs were absent in patient 2, ultralate potentials were absent in patients 1 and 2. Skin biopsy showed a disease duration related reduction of unmyelinated and myelinated sensory fibers and a lack of unmyelinated autonomic fibers in all patients.

CONCLUSIONS

Our data suggest that Ross syndrome is a degenerative disorder involving progressive sudomotor fibers, and then epidermal sensory unmyelinated and myelinated fibers.

Cardiac sympathetic denervation in Ross syndrome demonstrated by MIBG-SPECT

We investigated cardiac sympathetic innervation by metaiodobenzylguanidine (MIBG) imaging in a patient with tonic pupils, loss of tendon reflexes, and segmental anhidrosis (Ross syndrome). Despite normal cardiovascular reflex tests, we observed a reduced global myocardial MIBG uptake as well as a regional uptake defect over the posterolateral cardiac territory indicating left ventricular peripheral sympathetic denervation. MIBG imaging seems to be a useful noninvasive diagnostic method for detection of early--possibly subclinical--cardiac autonomic impairment in Ross syndrome and provides further evidence of injury to postganglionic autonomic neurons as the underlying pathological mechanism of the disease.

Selective degeneration of sudomotor fibers in Ross syndrome and successful treatment of compensatory hyperhidrosis with botulinum toxin

We report a 5-year follow-up of a patient with Ross syndrome. A biopsy of the anhidrotic skin immunostained with protein gene product 9.5 visualized by confocal microscopy revealed selective loss of sudomotor fibers, whereas epidermal innervation remained intact, providing the first morphologic evidence of selective loss of sudomotor fibers in this syndrome. Among the different treatment strategies employed for the patient's disabling segmental hyperhidrosis, intracutaneous injection of botulinum toxin A was the most helpful.

Electrophysiological study of a case of diffuse loss of sweating with segmental hyperhidrosis associated with areflexia

Electrophysiological investigations were carried out on a 43 year-old man with segmental hyperhidrosis in three radicular territories, generalized anhidrosis elsewhere and areflexia. A recurrent labial herpetic rash and a history of sweating disorders in his grandfather were the only associated clinical data. Sympathetic skin response was found to be absent in anhidrotic territories, including the hands and feet, although it was present in hyperhidrotic territories. Peripheral adrenergic sympathetic fibers evaluated by photoplethysmography were normally responsive, as were visceral vegetative regulations involved in cardiovascular control during postural changes or exercise. The present case is compared to the previously described Ross Syndrome, associating segmental hypohidrosis, areflexia and tonic pupils. Our results and observations in the literature are consistent with the occurrence of lesions affecting postganglionic cholinergic fibres of the sympathetic system.