Dr Iodice is a Consultant in Neurology and Autonomic Medicine and Honorary Associate Professor in Neurology at the University College of London. She has longstanding clinical and research interest in Autonomic Neurology, gained in three worldwide autonomic centres: Mayo Clinic, Rochester USA; Imperial College London and National Hospital for Neurology and Neurosurgery, London, UK.
Dr Iodice has been the clinical and academic lead of the Autonomic Unit at the National Hospital for Neurology and Neurosurgery, Queen Square, London since 2013.
Qualifying at University Federico II, Naples, Italy in 2003 and completed the residency in Neurology at the University Federico II, Naples, Italy in 2008.
She was award a Clinical Research Fellowship in Autonomic Medicine at Mayo Clinic Rochester Minnesota (USA) in 2007 where she began her research on the autonomic nervous system (ANS). In 2009, she was award the first Sir Roger Bannister fellowship in Autonomic Disorders and was awarded with a PhD in Autonomic Neurology from Imperial College, London. A respected speaker, she has presented at national and International meeting and has written several publications in major specialist journals that focus on the ANS in neurology and cardiovascular disorders and chapters in international textbooks of neurological and cardiovascular medicine.

Clinical evaluation and diagnosis of autonomic disorders starts with accurate clinical history.
The latter requires exploring the function of each of the autonomic domains (cardiovascular,
genitourinary, pupillary, secretomotor, gastrointestinal, sudomotor), establishing the time
course and the possibility of comorbidities and medication which might mimicking or
aggravate autonomic failure or autonomic intermittent disorders.
Clinical evaluation– Autonomic History
An accurate autonomic history will also help identifying whether there is a generalized or a
selective autonomic domain involvement.
Autonomic history aims to answer the following questions:
• Autonomic failure or intermittent/paroxysmal dysfunction?
• Localised or widespread ANS dysfunction?
• Time course: acute, chronic stable, progressive
• Iatrogenic disease
• Comorbidities as mimickers of a primary autonomic disorder (Eg. diabetes)
Autonomic Function Tests
Autonomic function tests are validated and non invasive function tests aimed at defining the
pattern of autonomic dysfunction (Does it affect parasympathetic, sympathetic or both?), and
the severity of autonomic failure and dysfunction. Testing is also informative in relation to
treatment for cardiovascular and sudomotor autonomic disorders.
In some patients, food ingestion may cause substantial hypotension even while supine, or
exacerbation of postural tachycardia. The cardiovascular autonomic responses to food
challenge can be tested using a liquid meal of mixed composition, with observations initially
in the supine position, to avoid the additional effect of gravity (Fig 2). The response to headup postural challenge before and after food ingestion, determines if food unmasks or
exacerbates orthostatic hypotension and/or symptoms.
In patients with autonomic failure, elevations in blood pressure and heart rate during exercise
are lower compared to normal controls (Fig 3).
Hypertension in the supine position may complicate orthostatic hypotension in pure
autonomic failure (PAF) and parkinsonian disorders. The mechanisms include impaired
baroreflex activity, adrenoceptor supersensitivity, an increase in central blood volume
because of a shift from the periphery and the effects of drugs used to prevent orthostatic
hypotension. Ambulatory 24 BP monitoring is of help in evaluating the degree of supine
hypertension (Fig 4).
Sudomotor dysfunction
Anhidrosis or hypohidrosis is common in autonomic failure and differences in sweating may
first be noticed during exposure to warm temperatures. Occasionally, hyperhidrosis in
segmental areas may be a disconcerting symptom, as a compensatory response to diminished
sudomotor activity elsewhere. Facial and truncal hyperhidrosis may occur in Parkinson’s
disease.
Sudomotor function can be evaluated with the following testing:
• QSART
• Dynamic Sweat Test
• Sympathetic skin response
• Silastic imprint
• Thermoregulatory Sweat Test (TST)
TST separated best MSA from PD with only minimal overlap. However, no single test has
sufficient sensitivity or specificity by itself but a cluster of autonomic dysfunction will
distinguish MSA from PD.
Useful References
1. William P Cheshire, Roy Freeman, Christopher H Gibbons, Pietro Cortelli, Gregor K
Wenning, Max J Hilz, Judith M Spies, Axel Lipp, Paola Sandroni, Naoki
Wada, Akiko Mano, Hyun Ah Kim, Kurt Kimpinski, Valeria Iodice, Juan
Idiáquez, Pariwat Thaisetthawatkul, Elizabeth A Coon, Phillip A Low, Wolfgang
Singer . Electrodiagnostic assessment of the autonomic nervous system: A consensus
statement endorsed by the American Autonomic Society, American Academy of
Neurology, and the International Federation of Clinical Neurophysiology. Clin
Neurophysiology. 2021 Feb;132(2):666-682.
2. Mathias CJ., Low D., Iodice V., and Bannister R. Investigations of autonomic
disorders. Autonomic Failure : A Texbook of Clinical Disorders of the Autonomic
Nervous System. 5th Edition. Oxford University Press, Oxford, 2011.
3. Iodice V., Low D., Vichayanrat E., and Mathias CJ. Cardiovascular Autonomic
Dysfunction in Parkinson’s Disease and Parkinsonian Syndromes. Eds. M. Ebadi and
R.F. Pfeiffer. Florida: CRC Press. 2011.