Justifying an organic differential diagnosis

John O’Donovan

True story about one of my friends doing MRCPsych Part 2

• “What’s your differential?” • “Oh, schizophrenia, schizoaffective disorder, mood

disorder and of course organic”• “Which particular organic process?”• “oh you know, all of them potentially”• “No, I don’t know, which ones specifically”• “oh you know, strokes and stuff like that..”• At this point the conversation became very unpleasant

and remained so thereafter.• She failed.

Basic rules

• Differential diagnostic lists should by definition be brief.

• Offering an organic option is in fact stating that there is an underlying brain disorder or systemic disorder causing the presentation

• If this is patently not the case, then do not offer an organic differential

ICD-10

• F00 alzheimer’s • F01 vascular dementia • F02 dementia in other diseases-Pick’s, CJD, HIV, Parkinson’s

(note Lewy Body Disease is not there and neither are the FTDs properly)

• F03 unspecified dementia• F04 organic amnesic syndrome • F05 delirium note both F04 and F05 exclude alcohol and

other addictive substances• F06 organic brain disorders due to physical disease • F07 organic personality disorders

ICD 10• F06 Other mental disorders due to brain damage and dysfunction and to physical disease • F06.0 Organic hallucinosis

F06.1 Organic catatonic disorderF06.2 Organic delusional [schizophrenia-like] disorder

• F06.3 Organic mood [affective] disorder .30 Organic manic disorder • .31 Organic bipolar disorder

.32 Organic depressive disorder

.33 Organic mixed affective disorder • F06.4 Organic anxiety disorder

F06.5 Organic dissociative disorderF06.6 Organic emotionally labile [asthenic] disorder F06.7 Mild cognitive disorder

• .70 Not associated with a physical disorder • .71 Associated with a physical disorder • F06.8 Other specified mental disorders due to brain damage and dysfunction and to physical disease • F06.9 Unspecified mental disorder due to brain damage and dysfunction and to physical disease • F07 Personality and behavioural disorders due to brain disease, damage and dysfunction • F07.0 Organic personality disorder • F07.1 Postencephalitic syndrome • F07.2 Postconcussional syndrome • F07.8 Other organic personality and behavioural disorders due to brain disease, damage and dysfunction • F07.9 Unspecified mental disorder due to brain disease, damage and dysfunction • F09 Unspecified organic or symptomatic mental disorder

What about the other areas?

• F10-F19, addictions, NB withdrawal states are coded here.

• F10.6: amnesic syndrome secondary to alcohol.

• Therefore alcohol related brain damage goes into the alcohol block, not the organic block, although clearly there is an organic basis

The organic differential

• What suggests it?• Atypical features of a psychiatric presentation • Wrong age, wrong psychopathology, wrong

course, very much a gestalt phenomena • Evidence of cognitive impairment,

neurological signs or systemic illness of some type

Primary CNS versus Systemic

CNS • Cognitive problems • Seizures • Headache • Focal signs• Remember blood brain

barrier, primary CNS pathology, often does not cause any systemic abnormalities

Systemic affecting CNS• Systemic markers • General ill health • Systemic questions• Evidence of systemic

disease

Rare versus Common and causality

Rare illnesses• Mitochondrial disorders • Autoimmune encephalitis • Paraneoplastic syndromes• Primary or secondary CNS

vasculitis • Metabolic disorders, Niemann

Pick, metachromatic leucodystrophy and other leucodystrophies

• Wilson’s • Many others

Common

• Stroke • Epilepsy• Multiple sclerosis • Dementias particularly

Alzheimer’s disease• Primary brain tumors are rare• HIV in the right setting• Huntington’s• Parkinson’s/LBD

Think

• Do you believe it?• Have you ever seen it?• Schizophrenia is not an uncommon illness and

neither is BPAD or recurrent depression. • An uncommon presentation of a common

illness is always more common than a common presentation of an uncommon illness.

CLINICAL SCENARIOS 1

• 24 year old female medical student who presents to her GP with severe anxiety, weight loss of one stone and mild tachycardia.

• Can’t sleep very well, palpitations, just broken up with boyfriend.

• MSE: well groomed, thin, sweaty, cognitively intact, intermittently tearful and crying, not hallucinating or deluded.

• Physical exam: normal but pulse consistently 115

Grave’s Disease

Autoimmune Far more common in women Insidious onset Goitre, exopthalmos and pretibial myxedema

Not all that uncommon and is definitely associated with anxiety and panic as well as low mood.

Inv: TFTs, and thyroid stimulating autoantibodies

Clinical scenario 2

• 44 year old man with 18 month history of difficult to treat depression and severe psychomotor retardation, complaining of a painful right arm and being restless in bed at night.

• MSE: depressed with negative cognitions, retarded, cognitively normal.

• Physical: nil obvious• Bloods normal, CT and MRI normal

Parkinson’s Disease

50% of PD patients at onset of illness have a severe depressive episode

Frequently does not respond well to standard ADTs

When someone is depressed, mid life onset of depression, particularly if associated with movement problems, then consider

Clinical scenario 3

• 18 year old girl, presents with UTI in A/E having “pseudoseizures”

• No prior history, brother has epilepsy. • On IV antibiotics, C/O severe abdominal and loin pain• Basic bloods normal• MSE: orientated, C/O tummy pain, unusual affect

labile and tearful• Collateral: family describe her as moody and difficult. • CT brain done reluctantly in A/E is normal

Acute intermittent porphyria

Acute attacks of abdominal pain, seizures and central disturbance. In particular cognition and mood.

Diagnosis: biochemical urine and blood porphyrins.

That girl was real and she died.

Clinical scenario 4

• 28 year old man brought in by police from the street on a section as he was walking naked in traffic. In A/E singing loudly, walking around and irritable.

• MSE: accelerated and aggressive, elated mood, sexually suggestive to nurses

• Collateral: normally well, good job, long term history of epilepsy which is well controlled, mother attends service with bipolar and is on lithium. No recent seizures.

BPAD

Very little convincing evidence that this man has anything but bipolar disorder with first presentation of a manic episode.

Clinical scenario 5

• 29 year old woman with MCTD on her honeymoon in Australia. Begins to fight with husband in hotel at Ayer’s rock. GP goes out, It’s a domestic and legs it. Continues to be unwell for next three weeks, ultimately seen in Sydney and started on olanzapine.

• MSE: giggling, imprecisely orientated, Raynaud’s phenomena, mild alopecia.

• Bloods ESR elevated, creatinine 180, anaemic, dsDNA positive

SLE

Can cause anything

Vasculitis White matter disease All known psychiatric presentations have been reported in neuropsychiatric lupus

Should have evidence of systemic disease, inflamatory response and autoantibodies.

Clinical scenario 6

• 65 year old man, referred by GP with depression, 12 month history of sleep disturbance, complex visual hallucinations at night and restless legs, took overdose, wife notes that he is getting his words mixed up, not obvious on exam, complaining of problems with vision, not being fixed with new glasses, can’t see TV properly, treated with ADT starts to improve, then develops headache and scalp tenderness

• Diagnostic test performed

Glioblastoma

Non dominant parietal and temporal lobe glioblastoma

Clinical scenario 7

• 22 year old single woman. Presents with emotional lability, gross ataxia, supranuclear gaze palsy and massive splenomegaly.

• Family history of a rare metabolic disease already known.

Adult Niemann Pick Disease

Rare metabolic disorder which results in liver and spleen disease and white matter disorder in the brain.

Incredibly rare, reason for mentioning is that the hereditary leucodystrophies are associated with psychiatric presentations including psychosis and depression. They are not neurologically normal.

Clinical scenario 8

• 60 year old woman with long standing psychiatric history who presents with a manic episode complicated by generalised seizures. Get admitted under neurology, CT brain normal, CSF raised protein and some white cells, oligoclonal bands present, mild hypothyroidism, unusually high titres of anti thyroid antibodies

Hashimoto’s encephalopathy

rare illness Relapsing delirum like picture but frequently with lots of psychosis

Mechanism unknown but does respond to steroids and immunosurpression

Associated with high titres of anti thyroid antibodies

Clinical scenario 9

• 34 year old nurse who presents to A/E with dilated and fixed left pupil. This happens shortly after a very minor assault by a patient.

• No opthalmoplegia, no headache. Has urgent cerebral angiogram and MRI brain-both normal.

• Visual acuity inconsistent on examination, cocaine eye test done suggesting a local blockade

Malingering

Pharmacological blockade of the eye.

She left the hospital when it was suggested, never seen again.

Common themes of these patients

• They have evidence of something other than straightforward psychiatric disease.

• Nearly always present on history and exam and then confirmed via investigations.

• Take home message: be sparing in the use of organic as a differential diagnosis and remember that organic as a label means very little, until it is broken down further.

How to investigate?

CT brain• Fast • Cheap • Good for bone • Good for blood and mass

lesions • Does not visualise

brainstem, posterior fossa or hippocampi

MRI brain• Slower • More expensive • Much better resolution • Needs cautious

interpretation• Preferred option as a scan.

Imaging

Ct with SDH MRI with SDH

Get the most out of your neuroradiologist

• When writing a request, as much detail as possible, particularly anatomical detail and clinical detail.

• Occasionally a detailed letter and ideally face to face contact always produces a better service.

Get the most out of your local neurologist

• If a neurological disorder is suspected, then clearly get a neurology opinion which may ultimately prove a lot cheaper and is going to be a lot better for the patient.

Conclusion

• Be very precise when talking about organic aetiologies

• Do the basic tests • Be quick to refer • Odd presentations of madness are to be

expected.• Weird presentations of physical illness are

always far less likely but must be considered, sought out and treated.