Adie syndrome
Synonyms and keywords: Holmes-Adie Syndrome; Syndrome, Holmes-Adie; Syndrome, Adie's; Syndrome, Adie; Poorly Reacting Pupil; Holmes Adie Syndrome; Pupil, Poorly Reacting; Adie's Syndrome; Poorly Reacting Pupils; Pupils, Poorly Reacting

# Overview
Adie syndrome is characterized by abnormal pupillary function and loss of deep tendon reflexes. Abnormal pupillary functioning in adie syndrome consists of poor pupillary response to light but a better near response (light near dissociation). Damage to ciliary ganglion is responsible for pupillary abnormalities while the loss of deep tendon reflexes is caused by damage to dorsal root ganglion of spinal cord. Most of the times the cause of Adie syndrome is unknown, however, multiple pathologies can cause adie syndrome. It is a benign condition and is mostly diagnosed clinically. Management is mostly symptom directed and depends upon the underlying etiology

# Historical Perspective
-  syndrome]] was first discovered by William John Adie, a British neurologist, and Sir Gordon Morgan Holmes, an Irish neurologist in 1931. This syndrome was named after these 2 neurologists. 

# Classification
- Adie syndrome has a variant known as Ross syndrome, characterized by a triad of abnormal pupillary function, loss of deep tendon reflexes and sweating abnormalities. 

# Pathophysiology
- The pathogenesis of adie syndrome is characterized by damage to ciliary ganglion and dorsal root ganglion of spinal cord. Ciliary ganglion provides innervation to iris and ciliary muscle, thus controlling pupillary function and accommodation. Ciliary ganglion neurons responsible for accommodation are in a much greater number than the neurons controlling pupillary function. In adie syndrome, neurons/nerve fibers controlling both accommodation and pupillary function are damaged. But because of the large no. of neruons, accommodation is unaffected or minimally affected in adie syndrome. Some of the damaged nerve fibers start to regenerate. As nerve fibers innervating pupillary sphincter muscle are less in no. so very few of these fibers regenerate and are insufficient to restore the normal pupillary function. On the other hand, nerve fibers to the ciliary muscle also regenerate but may do so in an inappropriate fashion, providing innervation to pupillary sphincter muscle along with ciliary muscle. As the pupillary sphincter muscle is now innervated by fibers originally responsible for accommodation(which is a slower process than pupillary light reaction) so pupillary light response is impaired. 
- Loss of deep tendon reflexes in adie syndrome is caused by damage to dorsal root ganglion of spinal cord. 
- On microscopic histopathological analysis, degeneration of ciliary ganglion and atrophy of sphincter pupillae muscle, are characteristic findings of adie syndrome. Other findings associated with adie syndrome include degenration of sacral dorsal root ganglion, superior cervical ganglion and sciatic nerve. 

# Causes
Most commonly the cause of Adie syndrome is unknown(idiopathic). Less common causes of adie syndrome include infections like HIV, syphilis, varicella, lyme's disease, Human parvovirus-B19, autoimmune diseases like amyloidosis, sarcoidosis, guillain-barre syndrome, sjogren syndrome, polyarterities nodosa, vogt-koyanagi-haraga disease, ischemia caused by giant cell arteritis, migraine, lymphatoid granulomatosis, neuromuscular diseases like Lambert eaten syndrome, tumors affecting the orbit or choroid, orbital surgery, cardiovascular diseases, general anesthesia. ,anti-hu antibody.

# Differentiating adie syndrome from other Diseases
- Adie syndrome must be differentiated from other diseases that cause light near dissocation or miosis, or mydriasis, such as:
- Argyl-Robertson pupil
- 3rd cranial nerve palsy
- Horner's syndrome
- Ross syndrome
- Harlequin syndrome

# Epidemiology and Demographics
- The prevalence of adie syndrome is approximately 2 per 1000 individuals. 
- The annual incidence of adie syndrome is estimated to be  cases per 100,000 individuals. 

## Age
- Adie syndrome is more commonly observed among patients aged 25 to 45 years old. 

## Gender
- Females are more commonly affected with Adie pupil than males. 

## Race
- There is no racial predilection for adie syndrome.

# Risk Factors
- Common risk factors in the development of adie syndrome are infections, trauma, tumors, ischemia and autoimmune disorders.

# Natural History, Complications and Prognosis
- Early clinical features include accommodative paresis, impaired light reflex and loss of deep tendon reflexes. Accomodative paresis tends to improve overtime, however, impairment of pupillary light reaction and deep tendon reflexes is persistent and in some cases may worsen overtime.  
- Complications of adie syndrome include angle closure glaucoma and amblyopia. However, they occur very rarely.
- Prognosis is generally good. Adie syndrome has no associated mortality rate as it is a nonlife-threatening condition.  

# Diagnosis

## Diagnostic Criteria
- The diagnosis of  is made when both pupillary abnormalities and absence or impairment of deep tendon reflexes are present. Although, both of these features may not coexist. If only pupillary abnormalities are present then the condition is referred to as adie pupil. 

## History and Symptoms
- Symptoms of adie syndrome may include the following: 
- larger pupil size of one eye than the other eye
- sweating abnormalities
- reading difficulty
- Photophobia

## Physical Examination
- Physical examination may be remarkable for:
- absent or impaired pupillary light reflex
- absent deep tendon reflexes (most commonly achilles tendon is involved).
- Tonic near response of pupil with Light near dissociation.
- Segmental palsy of sphincter
- Irregular shape of pupil
- anisometropia
- hyperopia
- orthostatic hypotension
- hypersensitivity to cholinergic agonists

## Laboratory Findings
- There are no specific laboratory findings associated with adie syndrome.

## Electrocardiogram
There are no ECG findings associated with adie syndrome.

## X-ray
There are no x-ray findings associated with adie syndrome.

## Echocardiography or Ultrasound
There are no echocardiography/ultrasound findings associated with adie syndrome.

## CT scan
There are no CT scan findings associated with adie syndrome.

## MRI
There are no MRI findings associated with adie syndrome.

## Other Imaging Findings
There are no other imaging findings associated with adie syndrome.

## Other Diagnostic Studies
Low dose pilocarpine test may be helpful in the diagnosis of adie syndrome. Finding suggestive of adie pupil includes an exaggerated miotic reaction of the affected pupil as compared to the normal pupil. This exaggerated response to low dose pilocarpine occurs as a consequence of cholinergic denervation hypersensitivity of the affected pupil. Normal pupils do not respond to such low doses of pilocarpine. To rule out Ross syndrome, sweating abnormalities can be checked by using starch iodine test and spoon test. 

# Treatment

## Medical Therapy
- There is no treatment required for idiopathic adie syndrome. If any etiology is found, treatment should be directed against that etiology. Topical low dose pilocarpine or physostigmine can be used in symptomatic patients. For patients with accommodative paresis reading glasses should be prescribed.

## Surgery
- Thoracic sympathectomy can be performed for patients with excessive sweating.

## Prevention
- There are no primary preventive measures available for adie syndrome.